Image synchronization without input clock and data transmission clock in a pulsed hyperspectral, fluorescence, and laser mapping imaging system

ABSTRACT

Pulsed hyperspectral, fluorescence, and laser mapping imaging without input clock or data transmission clock is disclosed. A system includes an emitter for emitting pulses of electromagnetic radiation and an image sensor comprising a pixel array for sensing reflected electromagnetic radiation. The system includes a plurality of bidirectional data pads and a controller in communication with the image sensor. The system is such that at least a portion of the pulses of electromagnetic radiation emitted by the emitter comprises one or more of: electromagnetic radiation having a wavelength from about 513 nm to about 545 nm, from about 565 nm to about 585 nm, from about 900 nm to about 1000 nm, an excitation wavelength of electromagnetic radiation that causes a reagent to fluoresce, or a laser mapping pattern.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/864,227, filed Jun. 20, 2019, titled “IMAGE SENSORSYNCHRONIZATION WITHOUT INPUT CLOCK AND DATA TRANSMISSION CLOCK IN AHYPERSPECTRAL AND FLUORESCENCE IMAGING ENVIRONMENT,” which isincorporated herein by reference in its entirety, including but notlimited to those portions that specifically appear hereinafter, theincorporation by reference being made with the following exception: Inthe event that any portion of the above-referenced provisionalapplication is inconsistent with this application, this applicationsupersedes the above-referenced provisional application.

TECHNICAL FIELD

This disclosure is directed to digital imaging and is particularlydirected to hyperspectral imaging, fluorescence imaging, and/or lasermapping imaging in a light deficient environment.

BACKGROUND

Advances in technology have provided advances in imaging capabilitiesfor medical use. An endoscope may be used to look inside a body andexamine the interior of an organ or cavity of the body. Endoscopes areused for investigating a patient's symptoms, confirming a diagnosis, orproviding medical treatment. A medical endoscope may be used for viewinga variety of body systems and parts such as the gastrointestinal tract,the respiratory tract, the urinary tract, the abdominal cavity, and soforth. Endoscopes may further be used for surgical procedures such asplastic surgery procedures, procedures performed on joints or bones,procedures performed on the neurological system, procedures performedwithin the abdominal cavity, and so forth.

In some instances of endoscopic imaging, it may be beneficial ornecessary to view a space in color. A digital color image includes atleast three layers, or “color channels,” that cumulatively form an imagewith a range of hues. Each of the color channels measures the intensityand chrominance of light for a spectral band. Commonly, a digital colorimage includes a color channel for red, green, and blue spectral bandsof light (this may be referred to as a Red Green Blue or RGB image).Each of the red, green, and blue color channels include brightnessinformation for the red, green, or blue spectral band of light. Thebrightness information for the separate red, green, and blue layers arecombined to create the color image. Because a color image is made up ofseparate layers, a conventional digital camera image sensor includes acolor filter array that permits red, green, and blue visible lightwavelengths to hit selected pixel sensors. Each individual pixel sensorelement is made sensitive to red, green, or blue wavelengths and willonly return image data for that wavelength. The image data from thetotal array of pixel sensors is combined to generate the RGB image. Theat least three distinct types of pixel sensors consume significantphysical space such that the complete pixel array cannot fit in thesmall distal end of an endoscope.

Because a traditional image sensor cannot fit in the distal end of anendoscope, the image sensor is traditionally located in a handpiece unitof an endoscope that is held by an endoscope operator and is not placedwithin the body cavity. In such an endoscope, light is transmitted alongthe length of the endoscope from the handpiece unit to the distal end ofthe endoscope. This configuration has significant limitations.Endoscopes with this configuration are delicate and can be easilymisaligned or damaged when bumped or impacted during regular use. Thiscan significantly degrade the quality of the images and necessitate thatthe endoscope be frequently repaired or replaced.

The traditional endoscope with the image sensor placed in the handpieceunit is further limited to capturing only color images. However, in someimplementations, it may be desirable to capture images withfluorescence, hyperspectral, and/or laser mapping data in addition tocolor image data. Fluorescence imaging captures the emission of light bya substance that has absorbed electromagnetic radiation and “glows” asit emits a relaxation wavelength. Hyperspectral imaging can be used toidentify different materials, biological processes, and chemicalprocesses by emitting different partitions of electromagnetic radiationand assessing the spectral responses of materials. Laser mapping imagingcan capture the surface shape of objects and landscapes and measuredistances between objects within a scene. Laser mapping imaging mayfurther encompass tool tracking wherein the distances and/or dimensionsof tools within a scene can be tracked relative to each other, relativeto an imaging device, and/or relative to structures within the scene. Insome implementations, it may be desirable to use one or more offluorescence imaging, hyperspectral imaging, and/or laser mappingimaging in combination when imaging a scene.

However, applications of fluorescence, hyperspectral, and laser mappingtechnology known in the art typically require highly specializedequipment that may not be useful for multiple applications. Further,such technologies provides a limited view of an environment andtypically must be used in conjunction with multiple separate systems andmultiple separate image sensors that are made sensitive to specificbands of electromagnetic radiation. It is therefore desirable to developan imaging system that can be used in a space constrained environment togenerate fluorescence, hyperspectral, and or laser mapping imaging data.

In light of the foregoing, described herein are systems, methods, anddevices for fluorescence, hyperspectral, and laser mapping imaging in alight deficient environment. Such systems, methods, and devices mayprovide multiple datasets for identifying critical structures in a bodyand providing precise and valuable information about a body cavity.

BRIEF DESCRIPTION OF THE DRAWINGS

Non-limiting and non-exhaustive implementations of the disclosure aredescribed with reference to the following figures, wherein likereference numerals refer to like parts throughout the various viewsunless otherwise specified. Advantages of the disclosure will becomebetter understood with regard to the following description andaccompanying drawings where:

FIG. 1 is a schematic view of a system for digital imaging in a lightdeficient environment with a paired emitter and pixel array;

FIG. 2 is a system for providing illumination to a light deficientenvironment for endoscopic imaging;

FIG. 2A is a schematic diagram of complementary system hardware;

FIGS. 3A to 3D are illustrations of the operational cycles of a sensorused to construct an exposure frame;

FIG. 4A is a graphical representation of the operation of an embodimentof an electromagnetic emitter;

FIG. 4B is a graphical representation of varying the duration andmagnitude of the emitted electromagnetic pulse to provide exposurecontrol;

FIG. 5 is a graphical representation of an embodiment of the disclosurecombining the operational cycles of a sensor, the electromagneticemitter, and the emitted electromagnetic pulses of FIGS. 3A-4B, whichdemonstrate the imaging system during operation;

FIG. 6A is a schematic diagram of a process for recording a video withfull spectrum light over a period of time from t(0) to t(1);

FIG. 6B is a schematic diagram of a process for recording a video bypulsing portioned spectrum light over a period of time from t(0) tot(1);

FIGS. 7A-7E illustrate schematic views of the processes over an intervalof time for recording a frame of video for both full spectrum light andpartitioned spectrum light;

FIG. 8 is a schematic diagram of a regular operation sequence for animage sensor;

FIG. 9 is a schematic diagram of a sensor service stream that includes aclock-like signal inserted in the output data stream of a pixel array;

FIG. 10 is a schematic diagram of a clock training sequence that may bedeployed when the phase lock loop voltage drifts significantly far fromthe lock voltage;

FIG. 11 is a schematic diagram of a rolling readout row used to addressthe CDR specification concerned with the maximal number of bits betweentransitions to ensure the CDR does not lose its lock;

FIG. 12A is a schematic diagram of a conventional method for generatinga clock signal wherein an image sensor communicates with an off-chiposcillator;

FIG. 12B is a schematic diagram of a conventional method for generatinga clock signal that deploys an on-chip oscillator rather than anoff-chip oscillator;

FIG. 13 is a circuit diagram of a conventional phase lock loop;

FIG. 14 is a circuit diagram for clock management and data sequencingbetween a camera unit and an image sensor;

FIG. 15 is a circuit diagram for clock management and data sequencingbetween a camera unit and an image sensor;

FIG. 16 is a circuit diagram for clock management and data sequencingbetween a camera unit and an image sensor;

FIG. 17 is a circuit diagram for clock management and data sequencingbetween a camera unit and an image sensor;

FIG. 18 is a schematic diagram of a process flow that may be implementedby a camera unit implemented in a charge pump system;

FIG. 19 is a table listing signals and parameters that may be used by acamera unit;

FIG. 20 is a schematic diagram of a pattern reconstruction process forgenerating an RGB image with specialty data overlaid thereon by pulsingpartitioned spectrums of light;

FIGS. 21A-21C illustrate a light source having a plurality of emitters;

FIG. 22 illustrates a single optical fiber outputting via a diffuser atan output to illuminate a scene in a light deficient environment;

FIG. 23 illustrates a portion of the electromagnetic spectrum dividedinto a plurality of different sub-spectrums which may be emitted byemitters of a light source in accordance with the principles andteachings of the disclosure;

FIG. 24 is a schematic diagram illustrating a timing sequence foremission and readout for generating an image frame comprising aplurality of exposure frames resulting from differing partitions ofpulsed light;

FIG. 25 illustrates an imaging system including a single cut filter forfiltering wavelengths of electromagnetic radiation;

FIG. 26 illustrates an imaging system comprising a multiple cut filterfor filtering wavelengths of electromagnetic radiation;

FIG. 27 illustrates an example laser mapping pattern that may be pulsedby an imaging system;

FIGS. 28A and 28B illustrate an implementation having a plurality ofpixel arrays for producing a three-dimensional image in accordance withthe principles and teachings of the disclosure; and

FIGS. 29A and 29B illustrate a perspective view and a side view,respectively, of an implementation of an imaging sensor built on aplurality of substrates, wherein a plurality of pixel columns formingthe pixel array are located on the first substrate and a plurality ofcircuit columns are located on a second substrate and showing anelectrical connection and communication between one column of pixels toits associated or corresponding column of circuitry; and

FIGS. 30A and 30B illustrate a perspective view and a side view,respectively, of an implementation of an imaging sensor having aplurality of pixel arrays for producing a three-dimensional image,wherein the plurality of pixel arrays and the image sensor are built ona plurality of substrates.

DETAILED DESCRIPTION

Disclosed herein are systems, methods, and devices for digital imagingthat may be primarily suited to medical applications such as medicalendoscopic imaging. An embodiment of the disclosure is an endoscopicsystem for fluorescence, hyperspectral, and/or laser mapping imaging ofa light deficient environment.

Conventional endoscopes are designed such that the image sensor isplaced at a proximal end of the device within a handpiece unit. Thisconfiguration requires that incident light travel the length of theendoscope by way of precisely coupled optical elements. The preciseoptical elements can easily be misaligned during regular use, and thiscan lead to image distortion or image loss. Embodiments of thedisclosure place an image sensor within a distal end of the endoscopeitself. This provides greater optical simplicity when compared withimplementations known in the art. However, an acceptable solution tothis approach is by no means trivial and introduces its own set ofengineering challenges.

For digital imaging systems, the final quality of a digital imagedepends on the engineering details of the electronic capture processthat was used to generate the image. The perceived quality of an imageis dependent on the signal to noise ratio (SNR), dynamic range (DR),spatial resolution, perception of visible unnatural artifacts,perception of spatial distortion, and color fidelity of the image. Eachof these factors can be negatively impacted by decreasing the overallsize of the image sensor. Therefore, in an effort to increase theperceived quality of a resultant image frame, traditional cameras knownin the art include multiple image sensors or include an enlarged imagesensor. For example, high-end cameras that can produce high resolutionimages typically include at least three monochrome sensors that areprecisely coupled in an elaborate arrangement of prisms and filters.Another traditional solution is to use a single sensor with individualpixel-sized color filters fabricated on to the image sensor in a mosaicarrangement. The most popular mosaic arrangement is the Bayer pattern.An image sensor with a Bayer pattern can be inexpensive to fabricate butcannot achieve the image quality realized by the three-image sensorsolution implemented in high-end cameras. An additional undesirable sideeffect of the Bayer pattern is that the color segmentation patternintroduces artifacts in the resultant image frames, and these artifactscan be especially noticeable around black and white edges.

There can be a noticeable loss to image quality when the overall size ofan image sensor is minimized such that the image sensor can fit withinthe distal tip of an endoscope. The area of the pixel array of the imagesensor can be reduced by reducing the number of pixels and/or thesensing area of each individual pixel. Each of these modificationsimpacts the resolution, sensitivity, and dynamic range of the resultantimages. Traditional endoscopic imaging systems are geared toward sensingsteady broadband illumination and providing color information by virtueof segmented pixel arrays such as the Bayer pattern array. In light ofthe deficiencies associated with segmented pixel arrays, disclosedherein are alternative systems and methods that use a monochromatic (maybe referred to as “color agnostic”) pixel array that does not includeindividual pixel filters. In the embodiments disclosed herein, the colorinformation is provided by pulsing an emitter with different wavelengthsof electromagnetic radiation. The pulsed imaging system disclosed hereincan generate color images with hyperspectral, fluorescence, and/or lasermapping imaging data overlaid thereon.

In an embodiment, the color information is determined by capturingindependent exposure frames in response to pulses of differentwavelengths of electromagnetic radiation. The alternative pulses mayinclude red, green, and blue wavelengths for generating an RGB imageframe consisting of a red exposure frame, a green exposure frame, and ablue exposure frame. The image frame may further include data from aspecialty exposure frame overlaid on the RGB image frame. The specialtyexposure frame may include one or more of a hyperspectral exposureframe, a fluorescence exposure frame, and/or a laser mapping exposureframe. The laser mapping pulse may include a lase mapping, laserscanning, and/or tool tracking pattern such as a grid array, a dotarray, and so forth. The laser mapping pulse can be used to identifydimensions and distances within the scene, and further to generate athree-dimensional topology of the scene.

In an embodiment, the overall size of the image sensor is furtherreduced by reducing the number of pads on the image sensor chip. Asignificant portion of total chip area is consumed by individual bondpads on the image sensor chip. Each bond pad provides power andinput/output signals to and from the image sensor chip. In the systemsand methods disclosed herein, the imaging sensor pad count is reduced bynegating the need for an output clock or an input clock. An embodimentof the disclosure causes an imaging sensor of an endoscope to issue acontinuous stream of ones (1s) and zeroes (0s) on its data port(s) uponpower up. This causes a data receiver within the support electronics ofthe endoscope to synchronize using a Clock Data Recovery (CDR) circuitby way of clock training. In an embodiment, the continuous stream ofones and zeroes is enabled during normal operation by toggling oneconfiguration register bit. Once the data receiver locks into thistraining pattern, normal sensor imaging operation may proceed. The lockon the training pattern may be maintained by avoiding long periodswithout transmissions by including a single invert bit for the digitalvalue issued for each pixel of the image sensor.

In an embodiment, the data generated by the image sensor is synchronizedwithout an output clock. Traditional high speed data transmission isaccompanied by a clock for synchronization purposes. In the embodimentsdisclosed herein, the clock signal is embedded within the data streamitself by way of clock encoding. At the receiving end, the data streamis decoded to extract the clock and latch the data. This embodimentnegates the need for output clock pads on the image sensor chip andthereby reduces the overall size of the image sensor. In an embodiment,the endoscopic imaging system deploys the Clock Data Recovery (CDR)system to correctly latch incoming data. The CDR system uses an internalphase lock loop (PLL) to lock incoming data and latch the incoming data.The locking process uses data transitions for the phase lock loop toconverge. In an embodiment, a minimum number of transitions for initiallocking (and re-locking) is specified along with a maximum number ofconsecutive allowed bits without transition. This may be required forthe phase lock loop to remain locked.

In some instances, it is desirable to generate endoscopic imaging withmultiple data types or multiple images overlaid on one another. Forexample, it may be desirable to generate a color (“RGB”) image thatfurther includes hyperspectral, fluorescence, and/or laser mappingimaging data overlaid on the RGB image. An overlaid image of this naturemay enable a medical practitioner or computer program to identify highlyaccurate dimensions and three-dimensional topologies of critical bodystructures and further identify distances between tools and otherstructures within the light deficient environment based on the lasermapping data. Historically, this would require the use of multiplesensor systems including an image sensor for color imaging and one ormore additional image sensors for hyperspectral, fluorescence, or lasermapping imaging. In such systems, the multiple image sensors would havemultiple types of pixel sensors that are each sensitive to distinctranges of electromagnetic radiation. In systems known in the art, thisincludes the three separate types of pixel sensors for generating an RGBcolor image along with additional sensors and systems for generating thehyperspectral, fluorescence, and laser mapping data. These multipledifferent sensors consume a prohibitively large physical space andcannot be located at a distal tip of the endoscope. In systems known inthe art, the camera or cameras are not placed at the distal tip of theendoscope and are instead placed in an endoscope handpiece or roboticunit. This introduces numerous disadvantages and causes the endoscope tobe very delicate. The delicate endoscope may be damaged and imagequality may be degraded when the endoscope is bumped or impacted duringuse. Considering the foregoing, disclosed herein are systems, methods,and devices for endoscopic imaging in a light deficient environment. Thesystems, methods, and devices disclosed herein provide means foremploying multiple imaging techniques in a single imaging session whilepermitting one or more image sensors to be disposed in a distal tip ofthe endoscope.

The fluorescence imaging techniques discussed herein can be used incombination with one or more fluorescent reagents or dyes. The locationof a reagent can be identified by emitting an excitation wavelength ofelectromagnetic radiation that causes the reagent to fluoresce. Therelaxation wavelength emitted by the reagent can be read by an imagesensor to identify the location of the reagent within a scene. Dependingon the type of reagent that is used, the location of the reagent mayfurther indicate the location of critical structures such as certaintypes of tissue, cancerous cells versus non-cancerous cells, and soforth.

The hyperspectral imaging techniques discussed herein can be used to“see through” layers of tissue in the foreground of a scene to identifyspecific types of tissue and/or specific biological or chemicalprocesses. Hyperspectral imaging can be used in the medical context toquantitatively track the process of a disease and to determine tissuepathology. Additionally, hyperspectral imaging can be used to identifycritical structures such as nervous tissue, muscle tissue, cancerouscells, and so forth. In an embodiment, partitions of electromagneticradiation are pulsed, and data is gathered regarding the spectralresponses of different types of tissue in response to the partitions ofelectromagnetic radiation. A datastore of spectral responses can begenerated and analyzed to assess a scene and predict which tissues arepresent within the scene based on the sensed spectral responses.

The laser mapping imaging techniques discussed herein can be assessed togenerate a three-dimensional landscape map of a scene and to calculatedistances between objects within the scene. The laser mapping data canbe used in conjunction with fluorescence imaging and/or hyperspectralimaging to calculate the precise location and dimensions of criticalstructures. For example, the location and boundaries of a criticalstructure may be identified with the fluorescence and/or hyperspectralimaging. The precise measurements for the location of the criticalstructure, the dimensions of the critical structure, and the distancefrom the critical structure to other objects can then be calculatedbased on the laser mapping data.

Hyperspectral Imaging

In an embodiment, the systems, methods, and devices disclosed hereinprovide means for generating hyperspectral imaging data in a lightdeficient environment. Spectral imaging uses multiple bands across theelectromagnetic spectrum. This is different from conventional camerasthat only capture light across the three wavelengths based in thevisible spectrum that are discernable by the human eye, including thered, green, and blue wavelengths to generate an RGB image. Spectralimaging may use any wavelength bands in the electromagnetic spectrum,including infrared wavelengths, the visible spectrum, the ultravioletspectrum, x-ray wavelengths, or any suitable combination of variouswavelength bands.

Hyperspectral imaging was originally developed for applications inmining and geology. Unlike a normal camera image that provides limitedinformation to the human eye, hyperspectral imaging can identifyspecific minerals based on the spectral signatures of the differentminerals. Hyperspectral imaging can be useful even when captured inaerial images and can provide information about, for example, oil or gasleakages from pipelines or natural wells and their effects on nearbyvegetation. This information is collected based on the spectralsignatures of certain materials, objects, or processes that may beidentified by hyperspectral imaging.

Hyperspectral imaging includes spectroscopy and digital photography. Inan embodiment of hyperspectral imaging, a complete spectrum or somespectral information is collected at every pixel in an image plane. Thegoal of hyperspectral imaging may vary for different applications. Inone application, the goal of hyperspectral imaging is to obtain theentire electromagnetic spectrum of each pixel in an image scene. Thismay enable certain objects to be found that might otherwise not beidentifiable under the visible light wavelength bands. This may enablecertain materials or tissues to be identified with precision when thosematerials or tissues might not be identifiable under the visible lightwavelength bands. Further, this may enable certain processes to bedetected by capturing an image across all wavelengths of theelectromagnetic spectrum.

In an embodiment of the disclosure, an endoscope system illuminates asource and pulses electromagnetic radiation for spectral orhyperspectral imaging. Spectral imaging uses multiple bands across theelectromagnetic spectrum. This is different from conventional camerasthat only capture light across the three wavelengths based in thevisible spectrum that are discernable by the human eye, including thered, green, and blue wavelengths to generate an RGB image. Spectralimaging may use any wavelength bands in the electromagnetic spectrum,including infrared wavelengths, the visible spectrum, the ultravioletspectrum, x-ray wavelengths, or any suitable combination of variouswavelength bands. Spectral imaging may overlay imaging generated basedon non-visible bands (e.g., infrared) on top of imaging based on visiblebands (e.g. a standard RGB image) to provide additional information thatis easily discernable by a person or computer algorithm.

Hyperspectral imaging enables numerous advantages over conventionalimaging. The information obtained by hyperspectral imaging enablesmedical practitioners and/or computer-implemented programs to preciselyidentify certain tissues or conditions that may not be possible toidentify with RGB imaging. Additionally, hyperspectral imaging may beused during medical procedures to provide image-guided surgery thatenables a medical practitioner to, for example, view tissues locatedbehind certain tissues or fluids, identify atypical cancerous cells incontrast with typical healthy cells, identify certain tissues orconditions, identify critical structures, and so forth. Hyperspectralimaging provides specialized diagnostic information about tissuephysiology, morphology, and composition that cannot be generated withconventional imaging.

Hyperspectral imaging may provide particular advantages overconventional imaging in medical applications. The information obtainedby hyperspectral imaging can enable medical practitioners and/orcomputer-implemented programs to precisely identify certain tissues orconditions that may lead to diagnoses that may not be possible or may beless accurate if using conventional imaging such as RGB imaging.Additionally, hyperspectral imaging may be used during medicalprocedures to provide image-guided surgery that may enable a medicalpractitioner to, for example, view tissues located behind certaintissues or fluids, identify atypical cancerous cells in contrast withtypical healthy cells, identify certain tissues or conditions, identifycritical structures and so forth. Hyperspectral imaging may providespecialized diagnostic information about tissue physiology, morphology,and composition that cannot be generated with conventional imaging.

Endoscopic hyperspectral imaging may present advantages overconventional imaging in various applications and implementations of thedisclosure. In medical implementations, endoscopic hyperspectral imagingmay permit a practitioner or computer-implemented program to discern,for example, nervous tissue, muscle tissue, various vessels, thedirection of blood flow, and so forth. Hyperspectral imaging may enableatypical cancerous tissue to be precisely differentiated from typicalhealthy tissue and may therefore enable a practitioner orcomputer-implemented program to discern the boundary of a canceroustumor during an operation or investigative imaging. Additionally,hyperspectral imaging in a light deficient environment as disclosedherein may be combined with the use of a reagent or dye to enablefurther differentiation between certain tissues or substances. In suchan embodiment, a reagent or dye may be fluoresced by a specificwavelength band in the electromagnetic spectrum and therefore provideinformation specific to the purpose of that reagent or dye. The systems,methods, and devices disclosed herein may enable any number ofwavelength bands to be pulsed such that one or more reagents or dyes maybe fluoresced at different times, and further so that one or morepartitions of electromagnetic radiation may be pulsed for hyperspectralimaging in the same imaging session. In certain implementations, thisenables the identification or investigation of a number of medicalconditions during a single imaging procedure.

Fluorescence Imaging

The systems, methods, and devices disclosed herein provide means forgenerating fluorescence imaging data in a light deficient environment.The fluorescence imaging data may be used to identify certain materials,tissues, components, or processes within a body cavity or other lightdeficient environment. In certain embodiments, fluorescence imaging isprovided to a medical practitioner or computer-implemented program toenable the identification of certain structures or tissues within abody. Such fluorescence imaging data may be overlaid on black-and-whiteor RGB images to provide additional information and context.

Fluorescence is the emission of light by a substance that has absorbedlight or other electromagnetic radiation. Certain fluorescent materialsmay “glow” or emit a distinct color that is visible to the human eyewhen the fluorescent material is subjected to ultraviolet light or otherwavelengths of electromagnetic radiation. Certain fluorescent materialswill cease to glow nearly immediately when the radiation source stops.

Fluorescence occurs when an orbital electron of a molecule, atom, ornanostructure is excited by light or other electromagnetic radiation,and then relaxes to its ground state by emitting a photon from theexcited state. The specific frequencies of electromagnetic radiationthat excite the orbital electron, or are emitted by the photon duringrelaxation, are dependent on the particular atom, molecule, ornanostructure. In most cases, the light emitted by the substance has alonger wavelength, and therefore lower energy, than the radiation thatwas absorbed by the substance. However, when the absorbedelectromagnetic radiation is intense, it is possible for one electron toabsorb two photons. This two-photon absorption can lead to emission ofradiation having a shorter wavelength, and therefore higher energy, thanthe absorbed radiation. Additionally, the emitted radiation may also bethe same wavelength as the absorbed radiation.

Fluorescence imaging has numerous practical applications, includingmineralogy, gemology, medicine, spectroscopy for chemical sensors,detecting biological processes or signals, and so forth. Fluorescencemay particularly be used in biochemistry and medicine as anon-destructive means for tracking or analyzing biological molecules.The biological molecules, including certain tissues or structures, maybe tracked by analyzing the fluorescent emission of the biologicalmolecules after being excited by a certain wavelength of electromagneticradiation. However, relatively few cellular components are naturallyfluorescent. In certain implementations, it may be desirable tovisualize a certain tissue, structure, chemical process, or biologicalprocess that is not intrinsically fluorescent. In such animplementation, the body may be administered a dye or reagent that mayinclude a molecule, protein, or quantum dot having fluorescentproperties. The reagent or dye may then fluoresce after being excited bya certain wavelength of electromagnetic radiation. Different reagents ordyes may include different molecules, proteins, and/or quantum dots thatwill fluoresce at particular wavelengths of electromagnetic radiation.Thus, it may be necessary to excite the reagent or dye with aspecialized band of electromagnetic radiation to achieve fluorescenceand identify the desired tissue, structure, or process in the body.

Fluorescence imaging may provide valuable information in the medicalfield that may be used for diagnostic purposes and/or may be visualizedin real-time during a medical procedure. Specialized reagents or dyesmay be administered to a body to fluoresce certain tissues, structures,chemical processes, or biological processes. The fluorescence of thereagent or dye may highlight body structures such as blood vessels,nerves, particular organs, and so forth. Additionally, the fluorescenceof the reagent or dye may highlight conditions or diseases such ascancerous cells or cells experiencing a certain biological or chemicalprocess that may be associated with a condition or disease. Thefluorescence imaging may be used in real-time by a medical practitioneror computer program for differentiating between, for example, cancerousand non-cancerous cells during a surgical tumor extraction. Thefluorescence imaging may further be used as a non-destructive means fortracking and visualizing over time a condition in the body that wouldotherwise not be visible by the human eye or distinguishable in an RGBimage.

The systems, methods, and devices for generating fluorescence imagingdata may be used in coordination with reagents or dyes. Some reagents ordyes are known to attach to certain types of tissues and fluoresce atspecific wavelengths of the electromagnetic spectrum. In animplementation, a reagent or dye is administered to a patient that isconfigured to fluoresce when activated by certain wavelengths of light.The endoscopic imaging system disclosed herein is used to excite andfluoresce the reagent or dye. The fluorescence of the reagent or dye iscaptured by the endoscopic imaging system to aid in the identificationof tissues or structures in the body cavity. In an implementation, apatient is administered a plurality of reagents or dyes that are eachconfigured to fluoresce at different wavelengths and/or provide anindication of different structures, tissues, chemical reactions,biological processes, and so forth. In such an implementation, theendoscopic imaging system emits each of the applicable wavelengths tofluoresce each of the applicable reagents or dyes. This may negate theneed to perform individual imaging procedures for each of the pluralityof reagents or dyes.

Imaging reagents can enhance imaging capabilities in pharmaceutical,medical, biotechnology, diagnostic, and medical procedure industries.Many imaging techniques such as X-ray, computer tomography (CT),ultrasound, magnetic resonance imaging (MRI), and nuclear medicine,mainly analyze anatomy and morphology and are unable to detect changesat the molecular level. Fluorescent reagents, dyes, and probes,including quantum dot nanoparticles and fluorescent proteins, assistmedical imaging technologies by providing additional information aboutcertain tissues, structures, chemical processes, and/or biologicalprocesses that are present within the imaging region. Imaging usingfluorescent reagents enables cell tracking and/or the tracking ofcertain molecular biomarkers. Fluorescent reagents may be applied forimaging cancer, infection, inflammation, stem cell biology, and others.Numerous fluorescent reagents and dyes are being developed and appliedfor visualizing and tracking biological processes in a non-destructivemanner. Such fluorescent reagents may be excited by a certain wavelengthor band of wavelengths of electromagnetic radiation. Similarly, thosefluorescent reagents may emit relaxation energy at a certain wavelengthor band of wavelengths when fluorescing, and the emitted relaxationenergy may be read by a sensor to determine the location and/orboundaries of the reagent or dye.

In an embodiment of the disclosure, an endoscopic imaging system pulseselectromagnetic radiation for exciting an electron in a fluorescentreagent or dye. The endoscopic imaging system may pulse multipledifferent wavelengths of electromagnetic radiation for fluorescingmultiple different reagents or dyes during a single imaging session. Theendoscope includes an image sensor that is sensitive to the relaxationwavelength(s) of the one or more reagents or dyes. The imaging datagenerated by the image sensor can be used to identify a location andboundary of the one or more reagents or dyes. The endoscope system mayfurther pulse electromagnetic radiation in red, green, and blue bands ofvisible light such that the fluorescence imaging can be overlaid on anRGB video stream.

Laser Mapping Imaging

In an embodiment, the systems, methods, and devices disclosed hereinprovide means for generating laser mapping data with an endoscopicimaging system. Laser mapping data can be used to determine precisemeasurements and topographical outlines of a scene. In oneimplementation, laser mapping data is used to determine precisemeasurements between, for example, structures or organs in a bodycavity, devices or tools in the body cavity, and/or critical structuresin the body cavity. As discussed herein, the term “laser mapping” mayencompass technologies referred to as laser mapping, laser scanning,topographical scanning, three-dimensional scanning, laser tracking, tooltracking, and others. A laser mapping exposure frame as discussed hereinmay include topographical data for a scene, dimensions between objectsor structures within a scene, dimensions or distances for tools orobjects within a scene, and so forth.

Laser mapping generally includes the controlled deflection of laserbeams. Within the field of three-dimensional object scanning, lasermapping combines controlled steering of laser beams with a laserrangefinder. By taking a distance measurement at every direction, thelaser rangefinder can rapidly capture the surface shape of objects,tools, and landscapes. Construction of a full three-dimensional topologymay include combining multiple surface models that are obtained fromdifferent viewing angles. Various measurement systems and methods existin the art for applications in archaeology, geography, atmosphericphysics, autonomous vehicles, and others. One such system includes lightdetection and ranging (LIDAR), which is a three-dimensional lasermapping system. LIDAR has been applied in navigation systems such asairplanes or satellites to determine position and orientation of asensor in combination with other systems and sensors. LIDAR uses activesensors to illuminate an object and detect energy that is reflected offthe object and back to a sensor.

As discussed herein, the term “laser mapping” includes laser tracking.Laser tracking, or the use of lasers for tool tracking, measures objectsby determining the positions of optical targets held against thoseobjects. Laser trackers can be accurate to the order of 0.025 mm over adistance of several meters. In an embodiment, an endoscopic imagingsystem pulses light for use in conjunction with a laser tracking systemsuch that the position or tools within a scene can be tracked andmeasured. In such an embodiment, the endoscopic imaging system may pulsea laser tracking pattern on a tool, object, or other structure within ascene being imaged by the endoscopic imaging system. A target may beplaced on the tool, object, or other structure within the scene.Measurements between the endoscopic imaging system and the target can betriggered and taken at selected points such that the position of thetarget (and the tool, object, or other structure to which the target isaffixed) can be tracked by the endoscopic imaging system.

Pulsed Imaging

Some implementations of the disclosure include aspects of a combinedsensor and system design that allows for high definition imaging withreduced pixel counts in a controlled illumination environment. This isaccomplished with frame-by-frame pulsing of a single-color wavelengthand switching or alternating each frame between a single, differentcolor wavelength using a controlled light source in conjunction withhigh frame capture rates and a specially designed correspondingmonochromatic sensor. Additionally, electromagnetic radiation outsidethe visible light spectrum may be pulsed to enable the generation of aspecialty image. The pixels may be color agnostic such that each pixelgenerates data for each pulse of electromagnetic radiation, includingpulses for red, green, and blue visible light wavelengths along withother wavelengths used for specialty imaging such as hyperspectral,fluorescence, and/or laser mapping imaging.

A system of the disclosure is an endoscopic imaging system for use in alight deficient environment. The system includes an endoscope comprisingan image sensor, wherein the image sensor is configured to sensereflected electromagnetic radiation for generating a plurality ofexposure frames that can be combined to generate an RGB image frame withspecialty imaging data overlaid thereon. The system includes an emitterfor emitting pulses of electromagnetic radiation. The system includes acontroller (may alternatively be referred to as a “control circuit” inelectronic communication with the image sensor and the emitter. Thecontroller controls a duty cycle of the emitter in response to signalscorresponding to a duty cycle of the emitter. The image sensor includesbidirectional pads that can send and receive information. Thebidirectional pads of the image sensor operate in a frame period dividedinto three defined states, including a rolling readout state, a serviceline state, and a configuration state. The system includes an oscillatordisposed in the controller and a frequency detector connected to thecontroller. The frequency detector controls a clock frequency of theimage sensor in response to signals from the controller that correspondto the frequency of the oscillator. The system is such that clock signaldata is transmitted from the bidirectional pads of the image sensor tothe controller during the service line phase and the configurationphase. The system is such that exposure frames are synchronized withoutthe use of an input clock or a data transmission clock.

For the purposes of promoting an understanding of the principles inaccordance with the disclosure, reference will now be made to theembodiments illustrated in the drawings and specific language will beused to describe the same. It will nevertheless be understood that nolimitation of the scope of the disclosure is thereby intended. Anyalterations and further modifications of the inventive featuresillustrated herein, and any additional applications of the principles ofthe disclosure as illustrated herein, which would normally occur to oneskilled in the relevant art and having possession of this disclosure,are to be considered within the scope of the disclosure claimed.

Before the structure, systems and methods for producing an image in alight deficient environment are disclosed and described, it is to beunderstood that this disclosure is not limited to the particularstructures, configurations, process steps, and materials disclosedherein as such structures, configurations, process steps, and materialsmay vary somewhat. It is also to be understood that the terminologyemployed herein is used for the purpose of describing particularembodiments only and is not intended to be limiting since the scope ofthe disclosure will be limited only by the appended claims andequivalents thereof.

In describing and claiming the subject matter of the disclosure, thefollowing terminology will be used in accordance with the definitionsset out below.

It must be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the context clearly dictates otherwise.

As used herein, the terms “comprising,” “including,” “containing,”“characterized by,” and grammatical equivalents thereof are inclusive oropen-ended terms that do not exclude additional, unrecited elements ormethod steps.

As used herein, the phrase “consisting of” and grammatical equivalentsthereof exclude any element or step not specified in the claim.

As used herein, the phrase “consisting essentially of” and grammaticalequivalents thereof limit the scope of a claim to the specifiedmaterials or steps and those that do not materially affect the basic andnovel characteristic or characteristics of the claimed disclosure.

As used herein, the term “proximal” shall refer broadly to the conceptof a portion nearest an origin.

As used herein, the term “distal” shall generally refer to the oppositeof proximal, and thus to the concept of a portion farther from anorigin, or a furthest portion, depending upon the context.

As used herein, color sensors or multi spectrum sensors are thosesensors known to have a color filter array (CFA) thereon to filter theincoming electromagnetic radiation into its separate components. In thevisual range of the electromagnetic spectrum, such a CFA may be built ona Bayer pattern or modification thereon to separate green, red and bluespectrum components of the light.

As used herein, monochromatic sensor refers to an unfiltered imagingsensor. Since the pixels are color agnostic, the effective spatialresolution is appreciably higher than for their color (typicallyBayer-pattern filtered) counterparts in conventional single-sensorcameras. Monochromatic sensors may also have higher quantum efficiencybecause fewer incident photons are wasted between individual pixels.

As used herein, an emitter is a device that is capable of generating andemitting electromagnetic pulses. Various embodiments of emitters may beconfigured to emit pulses and have very specific frequencies or rangesof frequencies from within the entire electromagnetic spectrum. Pulsesmay comprise wavelengths from the visible and non-visible ranges. Anemitter may be cycled on and off to produce a pulse or may produce apulse with a shutter mechanism. An emitter may have variable poweroutput levels or may be controlled with a secondary device such as anaperture or filter. An emitter may emit broad spectrum or full spectrumelectromagnetic radiation that may produce pulses through colorfiltering or shuttering. An emitter may comprise a plurality ofelectromagnetic sources that act individually or in concert.

It should be noted that as used herein the term “light” is both aparticle and a wavelength and is intended to denote electromagneticradiation that is detectable by a pixel array 122 and may includewavelengths from the visible and non-visible spectrums ofelectromagnetic radiation. The term “partition” is used herein to mean apre-determined range of wavelengths of the electromagnetic spectrum thatis less than the entire spectrum, or in other words, wavelengths thatmake up some portion of the electromagnetic spectrum. As used herein, anemitter is a light source that may be controllable as to the portion ofthe electromagnetic spectrum that is emitted or that may operate as tothe physics of its components, the intensity of the emissions, or theduration of the emission, or all the above. An emitter may emit light inany dithered, diffused, or collimated emission and may be controlleddigitally or through analog methods or systems. As used herein, anelectromagnetic emitter is a source of a burst of electromagnetic energyand includes light sources, such as lasers, LEDs, incandescent light, orany light source that can be digitally controlled.

Referring now to the figures, FIG. 1 illustrates a schematic diagram ofa system 100 for sequential pulsed imaging in a light deficientenvironment. The system 100 can be deployed to generate an RGB imagewith specialty data overlaid on the RGB image. The system 100 includesan emitter 102 and a pixel array 122. The emitter 102 pulses a partitionof electromagnetic radiation in the light deficient environment 112 andthe pixel array 122 senses instances of reflected electromagneticradiation. The emitter 102 and the pixel array 122 work in sequence suchthat one or more pulses of a partition of electromagnetic radiationresults in image data sensed by the pixel array 122.

It should be noted that as used herein the term “light” is both aparticle and a wavelength and is intended to denote electromagneticradiation that is detectable by a pixel array 122 and may includewavelengths from the visible and non-visible spectrums ofelectromagnetic radiation. The term “partition” is used herein to mean apre-determined range of wavelengths of the electromagnetic spectrum thatis less than the entire spectrum, or in other words, wavelengths thatmake up some portion of the electromagnetic spectrum. As used herein, anemitter is a light source that may be controllable as to the portion ofthe electromagnetic spectrum that is emitted or that may operate as tothe physics of its components, the intensity of the emissions, or theduration of the emission, or all the above. An emitter may emit light inany dithered, diffused, or collimated emission and may be controlleddigitally or through analog methods or systems. As used herein, anelectromagnetic emitter is a source of a burst of electromagnetic energyand includes light sources, such as lasers, LEDs, incandescent light, orany light source that can be digitally controlled.

A pixel array 122 of an image sensor may be paired with the emitter 102electronically, such that the emitter 102 and the pixel array 122 aresynced during operation for both receiving the emissions and for theadjustments made within the system. The emitter 102 may be tuned to emitelectromagnetic radiation in the form of a laser, which may be pulsed toilluminate a light deficient environment 112. The emitter 102 may pulseat an interval that corresponds to the operation and functionality ofthe pixel array 122. The emitter 102 may pulse light in a plurality ofelectromagnetic partitions such that the pixel array receiveselectromagnetic energy and produces a dataset that corresponds in timewith each specific electromagnetic partition. For example, FIG. 1illustrates an implementation wherein the emitter 102 emits fourdifferent partitions of electromagnetic radiation, including red 104,green 106, blue 108 wavelengths, and a specialty 110 emission. Thespecialty 110 emission may include an excitation wavelength forfluorescing a reagent, a hyperspectral partition of electromagneticradiation, and/or a laser mapping pattern. The specialty 110 emissionmay include multiple separate emissions that are separate andindependent from one another. The specialty 110 emission may include acombination of an excitation wavelength for fluorescing a reagent and alaser mapping pattern, wherein the emissions are separate andindependent from one another. The data resulting from the separateemissions can be analyzed in tandem to identify a critical structurewithin a scene based on the fluorescence imaging data, and further toidentify the dimensions or positioning of the critical structure basedon the laser mapping data in combination with the fluorescence imagingdata. The specialty 110 emission may include a combination of ahyperspectral band of electromagnetic radiation and a laser mappingpattern, wherein the emissions are separate and independent from oneanother. The data resulting from the separate emissions can be analyzedin tandem to identify a critical structure within a scene based on thehyperspectral imaging data, and further to identify the dimensions orpositioning of the critical structure based on the laser mapping data incombination with the hyperspectral imaging data. In an embodiment, thespecialty 110 emission includes any desirable combination of emissionsthat may be combined with the data resulting from the pulsed red 104,pulsed green 106, and pulsed blue 108 emissions. The specialty 110emissions may be dispersed within a pulsing pattern such that thedifferent types of specialty 110 emissions are not pulsed as frequentlyas the pulsed red 104, pulsed green 106, and pulsed blue 108 emissions.

In an alternative embodiment not illustrated in FIG. 1, the pulsedemissions of light include a luminance (“Y”) emission, a red chrominance(“Cr”) emission, and a blue chrominance (“Cb”) emission in place of thepulsed red 104, pulsed green 106, and pulsed blue 108 emissions. In anembodiment, the controller or the emitter 102 modules the pulses ofelectromagnetic radiation to provide luminance and/or chrominanceinformation according to color transformation coefficients that convertlight energy from red, green, and blue light energy spaces to luminance,red chrominance, and blue chrominance light energy space. The pulsedemissions of light may further include modulated blue chrominance(“λY+Cb”) pulses and/or modulated red chrominance (“δY+Cr”) pulses.

The light deficient environment 112 includes structures, tissues, andother elements that reflect a combination of red 114, green 116, and/orblue 118 light. A structure that is perceived as being red 114 willreflect back pulsed red 104 light. The reflection off the red structureresults in sensed red 105 by the pixel array 122 following the pulsedred 104 emission. The data sensed by the pixel array 122 results in ared exposure frame. A structure that is perceived as being green 116will reflect back pulsed green 106 light. The reflection off the greenstructure results in sensed green 107 by the pixel array 122 followingthe pulsed green 106 emission. The data sensed by the pixel array 122results in a green exposure frame. A structure that is perceived asbeing blue 118 will reflect back pulsed blue 108 light. The reflectionoff the blue structure results in sensed blue 109 by the pixel array 122following the pulsed blue 108 emission. The data sensed by the pixelarray 122 results in a blue exposure frame.

When a structure is a combination of colors, the structure will reflectback a combination of the pulsed red 104, pulsed green 106, and/orpulsed blue 108 emissions. For example, a structure that is perceived asbeing purple will reflect back light from the pulsed red 104 and pulsedblue 108 emissions. The resulting data sensed by the pixel array 122will indicate that light was reflected in the same region following thepulsed red 104 and pulsed blue 108 emissions. When the resultant redexposure frame and blue exposure frames are combined to form the RGBimage frame, the RGB image frame will indicate that the structure ispurple.

In an embodiment where the light deficient environment 112 includes afluorescent reagent or dye or includes one or more fluorescentstructures, tissues, or other elements, the pulsing scheme may includethe emission of a certain fluorescence excitation wavelength. Thecertain fluorescence excitation wavelength may be selected to fluorescea known fluorescent reagent, dye, or other structure. The fluorescentstructure will be sensitive to the fluorescence excitation wavelengthand will emit a fluorescence relaxation wavelength. The fluorescencerelaxation wavelength will be sensed by the pixel array 122 followingthe emission of the fluorescence excitation wavelength. The data sensedby the pixel array 122 results in a fluorescence exposure frame. Thefluorescence exposure frame may be combined with multiple other exposureframes to form an image frame. The data in the fluorescence exposureframe may be overlaid on an RGB image frame that includes data from ared exposure frame, a green exposure frame, and a blue exposure frame.

In an embodiment where the light deficient environment 112 includesstructures, tissues, or other materials that emit a spectral response tocertain partitions of the electromagnetic spectrum, the pulsing schememay include the emission of a hyperspectral partition of electromagneticradiation for the purpose of eliciting the spectral response from thestructures, tissues, or other materials present in the light deficientenvironment 112. The spectral response includes the emission orreflection of certain wavelengths of electromagnetic radiation. Thespectral response can be sensed by the pixel array 122 and result in ahyperspectral exposure frame. The hyperspectral exposure frame may becombined with multiple other exposure frames to form an image frame. Thedata in the hyperspectral exposure frame may be overlaid on an RGB imageframe that includes data from a red exposure frame, a green exposureframe, and a blue exposure frame.

In an embodiment, the pulsing scheme includes the emission of a lasermapping or tool tracking pattern. The reflected electromagneticradiation sensed by the pixel array 122 following the emission of thelaser mapping or tool tracking pattern results in a laser mappingexposure frame. The data in the laser mapping exposure frame may beprovided to a corresponding system to identify, for example, distancesbetween tools present in the light deficient environment 112, athree-dimensional surface topology of a scene in the light deficientenvironment 112, distances, dimensions, or positions of structures orobjects within the scene, and so forth. This data may be overlaid on anRGB image frame or otherwise provided to a user of the system.

The emitter 102 may be a laser emitter that is capable of emittingpulsed red 104 light for generating sensed red 105 data for identifyingred 114 elements within the light deficient environment 112. The emitter102 is further capable of emitting pulsed green 106 light for generatingsensed green 107 data for identifying green 116 elements within thelight deficient environment. The emitter 102 is further capable ofemitting pulsed blue 108 light for generating sensed blue 109 data foridentifying blue 118 elements within the light deficient environment.The emitter 102 is further capable of emitting a specialty 110 emissionfor mapping the topology 120 of a scene within the light deficientenvironment 112. The emitter 102 is capable of emitting the pulsed red104, pulsed green 106, pulsed blue 108, and pulsed specialty 110emissions in any desired sequence.

The pixel array 122 senses reflected electromagnetic radiation. Each ofthe sensed red 105, the sensed green 107, the sensed blue 109, and thesensed specialty 111 data can be referred to as an “exposure frame.” Thesensed specialty 111 may result in multiple separate exposure framesthat are separate and independent from one another. For example, thesensed specialty 111 may result in a fluorescence exposure frame, ahyperspectral exposure frame, and/or a laser mapping exposure framecomprising laser mapping data. Each exposure frame is assigned aspecific color or wavelength partition, wherein the assignment is basedon the timing of the pulsed color or wavelength partition from theemitter 102. The exposure frame in combination with the assignedspecific color or wavelength partition may be referred to as a dataset.Even though the pixels 122 are not color-dedicated, they can be assigneda color for any given dataset based on a priori information about theemitter.

For example, during operation, after pulsed red 104 light is pulsed inthe light deficient environment 112, the pixel array 122 sensesreflected electromagnetic radiation. The reflected electromagneticradiation results in an exposure frame, and the exposure frame iscatalogued as sensed red 105 data because it corresponds in time withthe pulsed red 104 light. The exposure frame in combination with anindication that it corresponds in time with the pulsed red 104 light isthe “dataset.” This is repeated for each partition of electromagneticradiation emitted by the emitter 102. The data created by the pixelarray 122 includes the sensed red 105 exposure frame identifying red 114components in the light deficient environment and corresponding in timewith the pulsed red 104 light. The data further includes the sensedgreen 107 exposure frame identifying green 116 components in the lightdeficient environment and corresponding in time with the pulsed green106 light. The data further includes the sensed blue 109 exposure frameidentifying blue 118 components in the light deficient environment andcorresponding in time with the pulsed blue 108 light. The data furtherincludes the sensed specialty 111 exposure frame identifying thetopology 120 and corresponding in time with the specialty 110 emission.

In one embodiment, three datasets representing RED, GREEN and BLUEelectromagnetic pulses are combined to form a single image frame. Thus,the information in a red exposure frame, a green exposure frame, and ablue exposure frame are combined to form a single RGB image frame. Oneor more additional datasets representing other wavelength partitions maybe overlaid on the single RGB image frame. The one or more additionaldatasets may represent, for example, the laser mapping data,fluorescence imaging data, and/or hyperspectral imaging data.

It will be appreciated that the disclosure is not limited to anyparticular color combination or any particular electromagneticpartition, and that any color combination or any electromagneticpartition may be used in place of RED, GREEN and BLUE, such as Cyan,Magenta and Yellow; Ultraviolet; infrared; any combination of theforegoing, or any other color combination, including all visible andnon-visible wavelengths, without departing from the scope of thedisclosure. In the figure, the light deficient environment 112 to beimaged includes red 114, green 116, and blue 118 portions, and furtherincludes a topology 120 that can be sensed and mapped into athree-dimensional rendering. As illustrated in the figure, the reflectedlight from the electromagnetic pulses only contains the data for theportion of the object having the specific color that corresponds to thepulsed color partition. Those separate color (or color interval)datasets can then be used to reconstruct the image by combining thedatasets at 126. The information in each of the multiple exposure frames(i.e., the multiple datasets) may be combined by a controller 124, acontrol unit, a camera control unit, the image sensor, an image signalprocessing pipeline, or some other computing resource that isconfigurable to process the multiple exposure frames and combine thedatasets at 126. The datasets may be combined to generate the singleimage frame within the endoscope unit itself or offsite by some otherprocessing resource.

FIG. 2 is a system 200 for providing illumination to a light deficientenvironment, such as for endoscopic imaging. The system 200 may be usedin combination with any of the systems, methods, or devices disclosedherein. The system 200 includes an emitter 202, a controller 204, ajumper waveguide 206, a waveguide connector 208, a lumen waveguide 210,a lumen 212, and an image sensor 214 with accompanying opticalcomponents (such as a lens). The emitter 202 (may be genericallyreferred to as a “light source”) generates light that travels throughthe jumper waveguide 206 and the lumen waveguide 210 to illuminate ascene at a distal end of the lumen 212. The emitter 202 may be used toemit any wavelength of electromagnetic energy including visiblewavelengths, infrared, ultraviolet, hyperspectral, fluorescenceexcitation, or other wavelengths. The lumen 212 may be inserted into apatient's body for imaging, such as during a procedure or examination.The light is output as illustrated by dashed lines 216. A sceneilluminated by the light may be captured using the image sensor 214 anddisplayed for a doctor or some other medical personnel. The controller204 may provide control signals to the emitter 202 to control whenillumination is provided to a scene. In one embodiment, the emitter 202and controller 204 are located within a camera control unit (CCU) orexternal console to which an endoscope is connected. If the image sensor214 includes a CMOS sensor, light may be periodically provided to thescene in a series of illumination pulses between readout periods of theimage sensor 214 during what is known as a blanking period. Thus, thelight may be pulsed in a controlled manner to avoid overlapping intoreadout periods of the image pixels in a pixel array of the image sensor214.

In one embodiment, the lumen waveguide 210 includes one or more opticalfibers. The optical fibers may be made of a low-cost material, such asplastic to allow for disposal of the lumen waveguide 210 and/or otherportions of an endoscope. In one embodiment, the lumen waveguide 210 isa single glass fiber having a diameter of 500 microns. The jumperwaveguide 206 may be permanently attached to the emitter 202. Forexample, a jumper waveguide 206 may receive light from an emitter withinthe emitter 202 and provide that light to the lumen waveguide 210 at thelocation of the connector 208. In one embodiment, the jumper waveguide106 includes one or more glass fibers. The jumper waveguide may includeany other type of waveguide for guiding light to the lumen waveguide210. The connector 208 may selectively couple the jumper waveguide 206to the lumen waveguide 210 and allow light within the jumper waveguide206 to pass to the lumen waveguide 210. In one embodiment, the lumenwaveguide 210 is directly coupled to a light source without anyintervening jumper waveguide 206.

The image sensor 214 includes a pixel array. In an embodiment, the imagesensor 214 includes two or more pixel arrays for generating athree-dimensional image. The image sensor 214 may constitute two moreimage sensors that each have an independent pixel array and can operateindependent of one another. The pixel array of the image sensor 214includes active pixels and optical black (“OB”) or optically blindpixels. The active pixels may be clear “color agnostic” pixels that arecapable of sensing imaging data for any wavelength of electromagneticradiation. The optical black pixels are read during a blanking period ofthe pixel array when the pixel array is “reset” or calibrated. In anembodiment, light is pulsed during the blanking period of the pixelarray when the optical black pixels are being read. After the opticalblack pixels have been read, the active pixels are read during a readoutperiod of the pixel array. The active pixels may be charged by theelectromagnetic radiation that is pulsed during the blanking period suchthat the active pixels are ready to be read by the image sensor duringthe readout period of the pixel array.

FIG. 2A is a schematic diagram of complementary system hardware such asa special purpose or general-purpose computer. Implementations withinthe scope of the present disclosure may also include physical and othernon-transitory computer readable media for carrying or storing computerexecutable instructions and/or data structures. Such computer readablemedia can be any available media that can be accessed by a generalpurpose or special purpose computer system. Computer readable media thatstores computer executable instructions are computer storage media(devices). Computer readable media that carry computer executableinstructions are transmission media. Thus, by way of example, and notlimitation, implementations of the disclosure can comprise at least twodistinctly different kinds of computer readable media: computer storagemedia (devices) and transmission media.

Computer storage media (devices) includes RAM, ROM, EEPROM, CD-ROM,solid state drives (“SSDs”) (e.g., based on RAM), Flash memory,phase-change memory (“PCM”), other types of memory, other optical diskstorage, magnetic disk storage or other magnetic storage devices, or anyother medium which can be used to store desired program code means inthe form of computer executable instructions or data structures andwhich can be accessed by a general purpose or special purpose computer.

A “network” is defined as one or more data links that enable thetransport of electronic data between computer systems and/or modulesand/or other electronic devices. In an implementation, a sensor andcamera control unit may be networked to communicate with each other, andother components, connected over the network to which they areconnected. When information is transferred or provided over a network oranother communications connection (either hardwired, wireless, or acombination of hardwired or wireless) to a computer, the computerproperly views the connection as a transmission medium. Transmissionsmedia can include a network and/or data links, which can be used tocarry desired program code means in the form of computer executableinstructions or data structures and which can be accessed by a generalpurpose or special purpose computer. Combinations of the above shouldalso be included within the scope of computer readable media.

Further, upon reaching various computer system components, program codemeans in the form of computer executable instructions or data structuresthat can be transferred automatically from transmission media tocomputer storage media (devices) (or vice versa). For example, computerexecutable instructions or data structures received over a network ordata link can be buffered in RAM within a network interface module(e.g., a “NIC”), and then eventually transferred to computer system RAMand/or to less volatile computer storage media (devices) at a computersystem. RAM can also include solid state drives (SSDs or PCIx based realtime memory tiered storage, such as FusionIO). Thus, it should beunderstood that computer storage media (devices) can be included incomputer system components that also (or even primarily) utilizetransmission media.

Computer executable instructions comprise, for example, instructions anddata which, when executed by one or more processors, cause ageneral-purpose computer, special purpose computer, or special purposeprocessing device to perform a certain function or group of functions.The computer executable instructions may be, for example, binaries,intermediate format instructions such as assembly language, or evensource code. Although the subject matter has been described in languagespecific to structural features and/or methodological acts, it is to beunderstood that the subject matter defined in the appended claims is notnecessarily limited to the described features or acts described above.Rather, the described features and acts are disclosed as example formsof implementing the claims.

Those skilled in the art will appreciate that the disclosure may bepracticed in network computing environments with many types of computersystem configurations, including, personal computers, desktop computers,laptop computers, message processors, control units, camera controlunits, hand-held devices, hand pieces, multi-processor systems,microprocessor-based or programmable consumer electronics, network PCs,minicomputers, mainframe computers, mobile telephones, PDAs, tablets,pagers, routers, switches, various storage devices, and the like. Itshould be noted that any of the above-mentioned computing devices may beprovided by or located within a brick and mortar location. Thedisclosure may also be practiced in distributed system environmentswhere local and remote computer systems, which are linked (either byhardwired data links, wireless data links, or by a combination ofhardwired and wireless data links) through a network, both performtasks. In a distributed system environment, program modules may belocated in both local and remote memory storage devices.

Further, where appropriate, functions described herein can be performedin one or more of: hardware, software, firmware, digital components, oranalog components. For example, one or more application specificintegrated circuits (ASICs) or field programmable gate arrays (FPGAs)can be programmed to carry out one or more of the systems and proceduresdescribed herein. Certain terms are used throughout the followingdescription and Claims to refer to particular system components. As oneskilled in the art will appreciate, components may be referred to bydifferent names. This document does not intend to distinguish betweencomponents that differ in name, but not function.

FIG. 2A is a block diagram illustrating an example computing device 250.Computing device 250 may be used to perform various procedures, such asthose discussed herein. Computing device 250 can function as a server, aclient, or any other computing entity. Computing device 250 can performvarious monitoring functions as discussed herein, and can execute one ormore application programs, such as the application programs describedherein. Computing device 250 can be any of a wide variety of computingdevices, such as a desktop computer, a notebook computer, a servercomputer, a handheld computer, camera control unit, tablet computer andthe like.

Computing device 250 includes one or more processor(s) 252, one or morememory device(s) 254, one or more interface(s) 256, one or more massstorage device(s) 258, one or more Input/Output (I/O) device(s) 260, anda display device 280 all of which are coupled to a bus 262. Processor(s)252 include one or more processors or controllers that executeinstructions stored in memory device(s) 254 and/or mass storagedevice(s) 258. Processor(s) 252 may also include various types ofcomputer readable media, such as cache memory.

Memory device(s) 254 include various computer readable media, such asvolatile memory (e.g., random access memory (RAM) 264) and/ornonvolatile memory (e.g., read-only memory (ROM) 266). Memory device(s)254 may also include rewritable ROM, such as Flash memory.

Mass storage device(s) 258 include various computer readable media, suchas magnetic tapes, magnetic disks, optical disks, solid-state memory(e.g., Flash memory), and so forth. As shown in FIG. 2, a particularmass storage device is a hard disk drive 274. Various drives may also beincluded in mass storage device(s) 258 to enable reading from and/orwriting to the various computer readable media. Mass storage device(s)258 include removable media 276 and/or non-removable media.

I/O device(s) 260 include various devices that allow data and/or otherinformation to be input to or retrieved from computing device 250.Example I/O device(s) 260 include digital imaging devices,electromagnetic sensors and emitters, cursor control devices, keyboards,keypads, microphones, monitors or other display devices, speakers,printers, network interface cards, modems, lenses, CCDs or other imagecapture devices, and the like.

Display device 280 includes any type of device capable of displayinginformation to one or more users of computing device 250. Examples ofdisplay device 280 include a monitor, display terminal, video projectiondevice, and the like.

Interface(s) 256 include various interfaces that allow computing device250 to interact with other systems, devices, or computing environments.Example interface(s) 256 may include any number of different networkinterfaces 270, such as interfaces to local area networks (LANs), widearea networks (WANs), wireless networks, and the Internet. Otherinterface(s) include user interface 268 and peripheral device interface272. The interface(s) 256 may also include one or more user interfaceelements 268. The interface(s) 256 may also include one or moreperipheral interfaces such as interfaces for printers, pointing devices(mice, track pad, etc.), keyboards, and the like.

Bus 262 allows processor(s) 252, memory device(s) 254, interface(s) 256,mass storage device(s) 258, and I/O device(s) 260 to communicate withone another, as well as other devices or components coupled to bus 262.Bus 262 represents one or more of several types of bus structures, suchas a system bus, PCI bus, IEEE 1394 bus, USB bus, and so forth.

For purposes of illustration, programs and other executable programcomponents are shown herein as discrete blocks, although it isunderstood that such programs and components may reside at various timesin different storage components of computing device 250 and are executedby processor(s) 252. Alternatively, the systems and procedures describedherein can be implemented in hardware, or a combination of hardware,software, and/or firmware. For example, one or more application specificintegrated circuits (ASICs) or field programmable gate arrays (FPGAs)can be programmed to carry out one or more of the systems and proceduresdescribed herein.

FIG. 3A illustrates the operational cycles of a sensor used in rollingreadout mode or during the sensor readout 300. The frame readout maystart at and may be represented by vertical line 310. The read-outperiod is represented by the diagonal or slanted line 302. The activepixels of the pixel array of the image sensor may be read out on a rowby row basis, the top of the downwards slanted edge being the sensor toprow 312 and the bottom of the downwards slanted edge being the sensorbottom row 314. The time between the last row readout and the nextreadout cycle may be called the blanking period 316. It should be notedthat some of the sensor pixel rows might be covered with a light shield(e.g., a metal coating or any other substantially black layer of anothermaterial type). These covered pixel rows may be referred to as opticalblack rows 318 and 320. Optical black rows 318 and 320 may be used asinput for correction algorithms. As shown in FIG. 3A, these opticalblack rows 318 and 320 may be located on the top of the pixel array orat the bottom of the pixel array or at the top and the bottom of thepixel array.

FIG. 3B illustrates a process of controlling the amount ofelectromagnetic radiation, e.g., light, that is exposed to a pixel,thereby integrated or accumulated by the pixel. It will be appreciatedthat photons are elementary particles of electromagnetic radiation.Photons are integrated, absorbed, or accumulated by each pixel andconverted into an electrical charge or current. An electronic shutter orrolling shutter (shown by dashed line 322) may be used to start theintegration time by resetting the pixel. The light will then integrateuntil the next readout phase. The position of the electronic shutter 322can be moved between two readout cycles 302 to control the pixelsaturation for a given amount of light. It should be noted that thistechnique allows for a constant integration time between two differentlines but introduces a delay when moving from top to bottom rows.

FIG. 3C illustrates the case where the electronic shutter 322 has beenremoved. In this configuration, the integration of the incoming lightmay start during readout 302 and may end at the next readout cycle 302,which also defines the start of the next integration.

FIG. 3D shows a configuration without an electronic shutter 322, butwith a controlled and pulsed light 330 during the blanking period 316.This ensures that all rows see the same light issued from the same lightpulse 330. In other words, each row will start its integration in a darkenvironment, which may be at the optical black back row 320 of read outframe (m) for a maximum light pulse width, and will then receive a lightstrobe and will end its integration in a dark environment, which may beat the optical black front row 318 of the next succeeding read out frame(m+1) for a maximum light pulse width. In the FIG. 3D example, the imagegenerated from the light pulse will be solely available during frame(m+1) readout without any interference with frames (m) and (m+2). Itshould be noted that the condition to have a light pulse to be read outonly in one frame and not interfere with neighboring frames is to havethe given light pulse firing during the blanking period 316. Because theoptical black rows 318, 320 are insensitive to light, the optical blackback rows 320 time of frame (m) and the optical black front rows 318time of frame (m+1) can be added to the blanking period 316 to determinethe maximum range of the firing time of the light pulse 330.

As illustrated in the FIG. 3A, a sensor may be cycled many times toreceive data for each pulsed color or wavelength (e.g., Red, Green,Blue, or other wavelength on the electromagnetic spectrum). Each cyclemay be timed. In an embodiment, the cycles may be timed to operatewithin an interval of 16.67 ms. In another embodiment, the cycles may betimed to operate within an interval of 8.3 ms. It will be appreciatedthat other timing intervals are contemplated by the disclosure and areintended to fall within the scope of this disclosure.

FIG. 4A graphically illustrates the operation of an embodiment of anelectromagnetic emitter. An emitter may be timed to correspond with thecycles of a sensor, such that electromagnetic radiation is emittedwithin the sensor operation cycle and/or during a portion of the sensoroperation cycle. FIG. 4A illustrates Pulse 1 at 402, Pulse 2 at 404, andPulse 3 at 406. In an embodiment, the emitter may pulse during thereadout period 302 of the sensor operation cycle. In an embodiment, theemitter may pulse during the blanking portion 316 of the sensoroperation cycle. In an embodiment, the emitter may pulse for a durationthat is during portions of two or more sensor operational cycles. In anembodiment, the emitter may begin a pulse during the blanking portion316, or during the optical black portion 320 of the readout period 302,and end the pulse during the readout period 302, or during the opticalblack portion 318 of the readout period 302 of the next succeedingcycle. It will be understood that any combination of the above isintended to fall within the scope of this disclosure as long as thepulse of the emitter and the cycle of the sensor correspond.

FIG. 4B graphically represents varying the duration and magnitude of theemitted electromagnetic pulse (e.g., Pulse 1 at 412, Pulse 2 at 414, andPulse 3 at 416) to control exposure. An emitter having a fixed outputmagnitude may be pulsed during any of the cycles noted above in relationto FIGS. 3D and 4A for an interval to provide the needed electromagneticenergy to the pixel array. An emitter having a fixed output magnitudemay be pulsed at a longer interval of time, thereby providing moreelectromagnetic energy to the pixels or the emitter may be pulsed at ashorter interval of time, thereby providing less electromagnetic energy.Whether a longer or shorter interval time is needed depends upon theoperational conditions.

In contrast to adjusting the interval of time the emitter pulses a fixedoutput magnitude, the magnitude of the emission itself may be increasedto provide more electromagnetic energy to the pixels. Similarly,decreasing the magnitude of the pulse provides less electromagneticenergy to the pixels. It should be noted that an embodiment of thesystem may have the ability to adjust both magnitude and durationconcurrently, if desired. Additionally, the sensor may be adjusted toincrease its sensitivity and duration as desired for optimal imagequality. FIG. 4B illustrates varying the magnitude and duration of thepulses. In the illustration, Pulse 1 at 412 has a higher magnitude orintensity than either Pulse 2 at 414 or Pulse 3 at 416. Additionally,Pulse 1 at 412 has a shorter duration than Pulse 2 at 414 or Pulse 3 at416, such that the electromagnetic energy provided by the pulse isillustrated by the area under the pulse shown in the illustration. Inthe illustration, Pulse 2 at 414 has a relatively low magnitude orintensity and a longer duration when compared to either Pulse 1 at 412or Pulse 3 at 416. Finally, in the illustration, Pulse 3 at 416 has anintermediate magnitude or intensity and duration, when compared to Pulse1 at 412 and Pulse 2 at 414.

FIG. 5 is a graphical representation of an embodiment of the disclosurecombining the operational cycles, the electromagnetic emitter, and theemitted electromagnetic pulses of FIGS. 3A-3D and 4A to demonstrate theimaging system during operation in accordance with the principles andteachings of the disclosure. As can be seen in the figure, theelectromagnetic emitter pulses the emissions primarily during theblanking period 316 of the image sensor such that the pixels will becharged and ready to read during the readout period 302 of the imagesensor cycle. The dashed lines in FIG. 5 represent the pulses ofelectromagnetic radiation (from FIG. 4A). The pulses of electromagneticradiation are primarily emitted during the blanking period 316 of theimage sensor but may overlap with the readout period 302 of the imagesensor.

An exposure frame includes the data read by the pixel array of the imagesensor during a readout period 302. The exposure frame may be combinedwith an indication of what type of pulse was emitted by the emitterprior to the readout period 302. The combination of the exposure frameand the indication of the pulse type may be referred to as a dataset.Multiple exposure frames may be combined to generate a black-and-whiteor RGB color image. Additionally, hyperspectral, fluorescence, and/orlaser mapping imaging data may be overlaid on a black-and-white or RGBimage.

In an embodiment, an RGB image frame is generated based on threeexposure frames, including a red exposure frame generated by the imagesensor subsequent to a red emission, a green exposure frame generated bythe image sensor subsequent to a green emission, and a blue exposureframe generated by the image sensor subsequent to a blue emission.Fluorescence imaging data may be overlaid on the RGB image frame. Thefluorescence imaging data may be drawn from one or more fluorescenceexposure frames. A fluorescence exposure frame includes data generatedby the image sensor during the readout period 302 subsequent to emissionof an excitation wavelength of electromagnetic radiation for exciting afluorescent reagent. The data sensed by the pixel array subsequent tothe excitation of the fluorescent reagent may be the relaxationwavelength emitted by the fluorescent reagent. The fluorescence exposureframe may include multiple fluorescence exposure frames that are eachgenerated by the image sensor subsequent to a different type offluorescence excitation emission. In an embodiment, the fluorescenceexposure frame includes multiple fluorescence exposure frames, includinga first fluorescence exposure frame generated by the image sensorsubsequent to an emission of electromagnetic radiation with a wavelengthfrom about 770 nm to about 790 and a second fluorescence exposure framegenerated by the image sensor subsequent to an emission ofelectromagnetic radiation with a wavelength from about 795 nm to about815 nm. The fluorescence exposure frame may include further additionalfluorescence exposure frames that are generated by the image sensorsubsequent to other fluorescence excitation emissions of light as neededbased on the imaging application.

In an embodiment, an exposure frame is the data sensed by the pixelarray during the readout period 302 that occurs subsequent to a blankingperiod 316. The emission of electromagnetic radiation is emitted duringthe blanking period 316. In an embodiment, a portion of the emission ofelectromagnetic radiation overlaps the readout period 316. The blankingperiod 316 occurs when optical black pixels of the pixel array are beingread and the readout period 302 occurs when active pixels of the pixelarray are being read. The blanking period 316 may overlap the readoutperiod 302.

FIGS. 6A and 6B illustrate processes for recording an image frame.Multiple image frames may be strung together to generate a video stream.A single image frame may include data from multiple exposure frames,wherein an exposure frame is the data sensed by a pixel array subsequentto an emission of electromagnetic radiation. FIG. 6A illustrates atraditional process that is typically implemented with a color imagesensor having a color filter array (CFA) for filtering out certainwavelengths of light per pixel. FIG. 6B is a process that is disclosedherein and can be implemented with a monochromatic “color agnostic”image sensor that is receptive to all wavelengths of electromagneticradiation.

The process illustrated in FIG. 6A occurs from time t(0) to time t(1).The process begins with a white light emission 602 and sensing whitelight 604. The image is processed and displayed at 606 based on thesensing at 604.

The process illustrated in FIG. 6B occurs from time t(0) to time t(1).The process begins with an emission of green light 612 and sensingreflected electromagnetic radiation 614 subsequent to the emission ofgreen light 612. The process continues with an emission of red light 616and sensing reflected electromagnetic radiation 618 subsequent to theemission of red light 616. The process continues with an emission ofblue light 620 and sensing reflected electromagnetic radiation 622subsequent to the emission of blue light 620. The process continues withone or more emissions of a specialty 624 emission and sensing reflectedelectromagnetic energy 626 subsequent to each of the one or moreemissions of the specialty 624 emission. The specialty emission mayinclude one or more separate emissions such as an excitation wavelengthof a fluorescent reagent, a hyperspectral emission, and/or a lasermapping emission. Each of the separate multiple specialty emissions maybe independently sensed by the image sensor to generate separate andindependent exposure frames. The image is processed and displayed at 628based on each of the sensed reflected electromagnetic energy instances614, 618, 622, and 626.

The process illustrated in FIG. 6B provides a higher resolution imageand provides a means for generating an RGB image that further includesspecialty data. When partitioned spectrums of light are used, (as inFIG. 6B) a sensor can be made sensitive to all wavelengths ofelectromagnetic energy. In the process illustrated in FIG. 6B, themonochromatic pixel array is instructed that it is sensingelectromagnetic energy from a predetermined partition of the fullspectrum of electromagnetic energy in each cycle. Therefore, to form animage the sensor need only be cycled with a plurality of differingpartitions from within the full spectrum of light. The final image isassembled based on the multiple cycles. Because the image from eachcolor partition frame cycle has a higher resolution (compared with a CFApixel array), the resultant image created when the partitioned lightframes are combined also has a higher resolution. In other words,because each and every pixel within the array (instead of, at most,every second pixel in a sensor with a CFA) is sensing the magnitudes ofenergy for a given pulse and a given scene, just fractions of timeapart, a higher resolution image is created for each scene.

As can be seen graphically in the embodiments illustrated in FIGS. 6Aand 6B between times t(0) and t(1), the sensor for the partitionedspectrum system in FIG. 6B has cycled at least four times for every oneof the full spectrum system in FIG. 6A. In an embodiment, a displaydevice (LCD panel) operates at 50-60 frames per second. In such anembodiment, the partitioned light system in FIG. 6B may operate at200-240 frames per second to maintain the continuity and smoothness ofthe displayed video. In other embodiments, there may be differentcapture and display frame rates. Furthermore, the average capture ratecould be any multiple of the display rate.

In an embodiment, it may be desired that not all partitions berepresented equally within the system frame rate. In other words, notall light sources have to be pulsed with the same regularity so as toemphasize and de-emphasize aspects of the recorded scene as desired bythe users. It should also be understood that non-visible and visiblepartitions of the electromagnetic spectrum may be pulsed together withina system with their respective data value being stitched into the videooutput as desired for display to a user.

An example embodiment may comprise a pulse cycle pattern as follows:

-   -   i. Green pulse;    -   ii. Red pulse;    -   iii. Blue pulse;    -   iv. Green pulse;    -   v. Red pulse;    -   vi. Blue pulse;    -   vii. Laser mapping pulsing scheme;    -   viii. Fluorescence excitation pulse;    -   ix. Hyperspectral pulse;    -   x. (Repeat)

A further example embodiment may comprise a pulse cycle pattern asfollows:

-   -   i. Green pulse;    -   ii. Red pulse;    -   iii. Blue pulse;    -   iv. Fluorescence excitation pulse;    -   v. Hyperspectral pulse;    -   vi. Green pulse;    -   vii. Red pulse;    -   viii. Blue pulse;    -   ix. Fluorescence excitation pulse;    -   x. Hyperspectral pulse;    -   xi. Laser mapping pulsing scheme;    -   xii. (Repeat)

An embodiment may comprise a pulse cycle pattern as follows:

-   -   i. Luminance pulse;    -   ii. Red chrominance pulse;    -   iii. Luminance pulse;    -   iv. Blue chrominance pulse;    -   v. Hyperspectral pulse;    -   vi. Fluorescence excitation pulse;    -   vii. Laser mapping pulse;    -   viii. (Repeat)

An embodiment may comprise a pulse cycle pattern as follows:

-   -   i. Luminance pulse;    -   ii. Red chrominance pulse;    -   iii. Luminance pulse;    -   iv. Blue chrominance pulse;    -   v. Luminance pulse;    -   vi. Red chrominance pulse;    -   vii. Luminance pulse;    -   viii. Blue chrominance pulse;    -   ix. Hyperspectral pulse;    -   x. Fluorescence excitation pulse;    -   xi. Laser mapping pulse;    -   xii. (Repeat)

The pulsing pattern may be altered to suit the imaging objectives for aspecific implementation. An example imaging objective is to obtainhyperspectral imaging data and fluorescence imaging data, and further toobtain laser mapping and/or tool tracking data that is based on analysisof the hyperspectral and/or fluorescence imaging data. In such anexample, the laser mapping and/or tool tracking data may be analyzed forcertain areas of a scene that have been highlighted by the hyperspectraland/or fluorescence imaging data. A further example imaging objective isto obtain hyperspectral imaging data or fluorescence imaging data, andfurther to obtain laser mapping and/or tool tracking data. A furtherexample imaging objective is to obtain laser mapping and/or tooltracking data. A further example imaging objective is to obtainhyperspectral imaging data. A further example imaging objective is toobtain fluorescence imaging data. It should be appreciated that theimaging objective may be specialized depending on the reason fordeploying the imaging system. Additionally, the imaging objective maychange during a single imaging session, and the pulsing pattern may bealtered to match the changing imaging objectives.

As can be seen in the example, a laser mapping partition may be pulsedat a rate differing from the rates of the other partition pulses. Thismay be done to emphasize a certain aspect of the scene, with the lasermapping data simply being overlaid with the other data in the videooutput to make the desired emphasis. It should be noted that theaddition of a laser mapping partition on top of the RED, GREEN, and BLUEpartitions does not necessarily require the serialized system to operateat four times the rate of a full spectrum non-serial system becauseevery partition does not have to be represented equally in the pulsepattern. As seen in the embodiment, the addition of a partition pulsethat is represented less in a pulse pattern (laser mapping in the aboveexample), would result in an increase of less than 20% of the cyclingspeed of the sensor to accommodate the irregular partition sampling.

In various embodiments, the pulse cycle pattern may further include anyof the following wavelengths in any suitable order. Such wavelengths maybe particularly suited for exciting a fluorescent reagent to generatefluorescence imaging data by sensing the relaxation emission of thefluorescent reagent based on a fluorescent reagent relaxation emission:

-   -   i. 770±20 nm;    -   ii. 770±10 nm;    -   iii. 770±5 nm;    -   iv. 790±20 nm;    -   v. 790±10 nm;    -   vi. 790±5 nm;    -   vii. 795±20 nm;    -   viii. 795±10 nm;    -   ix. 795±5 nm;    -   x. 815±20 nm;    -   xi. 815±10 nm;    -   xii. 815±5 nm;    -   xiii. 770 nm to 790 nm; and/or    -   xiv. 795 nm to 815 nm.

In various embodiments, the pulse cycle may further include any of thefollowing wavelengths in any suitable order. Such wavelengths may beparticularly suited for generating hyperspectral imaging data:

-   -   i. 513 nm to 545 nm;    -   ii. 565 nm to 585 nm;    -   iii. 900 nm to 1000 nm;    -   iv. 513±5 nm;    -   v. 513±10 nm;    -   vi. 513±20 nm;    -   vii. 513±30 nm;    -   viii. 513±35 nm;    -   ix. 545±5 nm;    -   x. 545±10 nm;    -   xi. 545±20 nm;    -   xii. 545±30 nm;    -   xiii. 545±35 nm;    -   xiv. 565±5 nm;    -   xv. 565±10 nm;    -   xvi. 565±20 nm;    -   xvii. 565±30 nm;    -   xviii. 565±35 nm;    -   xix. 585±5 nm;    -   xx. 585±10 nm;    -   xxi. 585±20 nm;    -   xxii. 585±30 nm;    -   xxiii. 585±35 nm;    -   xxiv. 900±5 nm;    -   xxv. 900±10 nm;    -   xxvi. 900±20 nm;    -   xxvii. 900±30 nm;    -   xxviii. 900±35 nm;    -   xxix. 1000±5 nm;    -   xxx. 1000±10 nm;    -   xxxi. 1000±20 nm;    -   xxxii. 1000±30 nm; or    -   xxxiii. 1000±35 nm.

The partition cycles may be divided so as to accommodate or approximatevarious imaging and video standards. In an embodiment, the partitioncycles may comprise pulses of electromagnetic energy in the Red, Green,and Blue spectrum as follows as illustrated best in FIGS. 7A-7D. In FIG.7A, the different light intensities have been achieved by modulating thelight pulse width or duration within the working range shown by thevertical grey dashed lines. In FIG. 7B, the different light intensitieshave been achieved by modulating the light power or the power of theelectromagnetic emitter, which may be a laser or LED emitter, butkeeping the pulse width or duration constant. FIG. 7C shows the casewhere both the light power and the light pulse width are beingmodulated, leading to greater flexibility. The partition cycles may useCyan Magenta Yellow (CMY), infrared, ultraviolet, hyperspectral, andfluorescence using a non-visible pulse source mixed with visible pulsesources and any other color space required to produce an image orapproximate a desired video standard that is currently known or yet tobe developed. It should also be understood that a system may be able toswitch between the color spaces on the fly to provide the desired imageoutput quality.

In an embodiment using color spaces Green-Blue-Green-Red (as seen inFIG. 7D) it may be desirous to pulse the luminance components more oftenthan the chrominance components because users are generally moresensitive to light magnitude differences than to light colordifferences. This principle can be exploited using a mono-chromaticsensor as illustrated in FIG. 7D. In FIG. 7D, green, which contains themost luminance information, may be pulsed more often or with moreintensity in a (G-B-G-R-G-B-G-R . . . ) scheme to obtain the luminancedata. Such a configuration would create a video stream that hasperceptively more detail, without creating and transmittingunperceivable data.

In an embodiment, duplicating the pulse of a weaker partition may beused to produce an output that has been adjusted for the weaker pulse.For example, blue laser light is considered weak relative to thesensitivity of silicon-based pixels and is difficult to produce incomparison to the red or green light, and therefore may be pulsed moreoften during a frame cycle to compensate for the weakness of the light.These additional pulses may be done serially over time or by usingmultiple lasers that simultaneously pulse to produce the desiredcompensation effect. It should be noted that by pulsing during ablanking period (time during which the sensor is not reading out thepixel array), the sensor is insensitive to differences/mismatchesbetween lasers of the same kind and simply accumulates the light for thedesired output. In another embodiment, the maximum light pulse range maybe different from frame to frame. This is shown in FIG. 7E, where thelight pulses are different from frame to frame. The sensor may be builtto be able to program different blanking periods with a repeatingpattern of two or three or four or n frames. In FIG. 7E, four differentlight pulses are illustrated, and Pulse 1 may repeat for example afterPulse 4 and may have a pattern of four frames with different blankingperiods. This technique can be used to place the most powerful partitionon the smallest blanking period and therefore allow the weakestpartition to have wider pulse on one of the next frames without the needof increasing the readout speed. The reconstructed frame can still havea regular pattern from frame to frame as it is constituted of manypulsed frames.

FIG. 8 is a schematic diagram of an embodiment of a regular operationsequence 800 for an image sensor. In an embodiment, one iteration of theregular operation sequence 800 results in one exposure frame generatedby the image sensor. In an alternative embodiment, one iteration of theregular operation sequence 800 results in multiple exposure framesgenerated by the image sensor. The regular operation sequence 800 may beimplemented for the purpose of endoscopic imaging in the presence ofcontrolled, pulsed illumination. Each frame period may comprise fourdistinct phases, which may be optimized for monochrome light pulsing andmultiple pixel illuminations.

The example regular operation sequence 800 illustrated in FIG. 8includes four phases, including phase 1, phase 2, phase 3, and phase 4.During phases 1 and 3, data is issued from the image sensor throughsensor data pads. These “service line” periods may be used for internaland external monitoring and for encoding certain types of non-pixel datawithin the line. This data can be used to synchronize the image sensorchip with the camera system and can further be used for data locking. Inan embodiment, imaging data from the pixel array is not output duringthe service line periods.

During phase 2, the sensor rolling readout is issued from the imagesensor through the sensor data pads. Phase 2 includes thesynchronization and readout of physical pixels in the pixel array of theimage sensor during a “rolling readout” period. The rolling readoutincludes imaging data sensed by the pixel array and results in one ormore exposure frames being generated by the image sensor.

During phase 4, image sensor configurations are received by the imagesensor through the sensor data pads. Phase 4 may be referred to as theconfiguration phase. During phase 4, the data lines are reversed toaccept incoming configuration commands rather than issue exiting pixeldata or non-pixel data. There is a risk that during phase 4, the ClockData Recovery (CDR) circuit in the camera unit will become unlocked andthe image sensor will not send any data transitions during a definedperiod. The service lines of phase 1 may be used to send a continuousstream of data transitions, however, to re-lock the camera unit CDRcircuit if required.

FIG. 9 is a schematic diagram of a sensor service stream 900. The sensorservice stream 900 includes a clock-like signal inserted in the outputdata stream of the pixel array at 902. In traditional systems, theclock-like signal would normally be included with pixel data in a cockrecovery lin. As shown in FIG. 9, a line header 904 is defined for thecamera system to differentiate between clock recovery lines and pixeldata lines. In an embodiment, the number of clock recovery lines isadjustable by way of a register setting.

FIG. 10 is a schematic diagram of a clock training sequence 1000 of animage sensor. The clock training sequence 1000 may be deployed when thephase lock loop (PLL) voltage drifts significantly far from the lockvoltage. This may be particularly common at startup of the image sensor.In the clock training sequence 1000, each of phase 1, phase 2, and phase3 from the regular operation sequence 800 is merged to form a continuousperiod of clock training.

The merged phase 1, phase 2, and phase 3 is a service line period.During the merged phase, information is issued from the image sensor.The information does not include signal samples from physical pixels ofthe pixel array and instead includes data pertaining to synchronizationof the image sensor chip with the camera system. The synchronizationdata can be used for data locking.

During phase 4, information is received by the image sensor. Phase 4 maybe referred to as the configuration phase. The duration of phase 4 maybe less than about 5-10 milliseconds. This short duration allows for alimited number of clock recovery lines. Therefore, the number oftransitions available to re-lock the system may be correspondingly low.In some implementations, this will not cause an issue because the phaselock loop (PLL) voltage of the camera unit Clock Data Recovery (CDR)does not have time to drift far from the lock voltage during phase 4. Inthe event the phase lock loop voltage drifts significantly far from thelock voltage, the receiver may need a significantly greater number oftransitions. In this instance, the clock training sequence 1000 may beused such that phases 1, 2, and 3 are merged to be a continuous clocktraining phase as shown in FIG. 10. Once the camera unit CDR has locked,the image sensor may resume normal operation as illustrated in theregular operation sequence 800 in FIG. 8. During the regular operationsequence 800, phase 1 may provide smaller adjustments needed forre-locking the camera unit CDR. Therefore, the CDR specificationregarding the minimal number of transitions to lock or re-lock may betaken care by combining the clock training sequence 100 and the regularoperation sequence 800.

FIG. 11 is a schematic diagram of a rolling readout row 1100. Therolling readout row 1100 is used to address the CDR specificationconcerned with the maximal number of bits between transitions to ensurethe CDR does not lose its lock. The rolling readout row 1100 may bebased on special encoding of pixel data captured by the pixel array ofthe image sensor.

In FIG. 11, the actual pixel data values may be 11 bits with the mostsignificant bits (MSB) transmitted first and the least significant bits(LSB) transmitted last. A twelfth bit may be added to each pixel's data.The twelfth bit is an inverted version of the eleventh bit, which is theleast significant true bit. This results in an encoding with very littleoverhead. A high transition rate may be obtained during transmission ofpixel data, thereby avoiding any possibility of the camera unit CDRbecoming unlocked.

FIGS. 12A and 12B illustrate schematic diagrams of two conventionalmethods for generating a clock signal for an image sensor 1202. In theimplementation shown in FIG. 12A, the image sensor 1202 communicateswith an off-chip oscillator. The off-chip oscillator may be a crystaloscillator and a phase lock loop (PLL) circuit. The implementation shownin FIG. 12A leads to precise results bud adds the burden of anadditional pad 1206 and an active component. The active component mayrequire low speed control programming that further increases theconductor count. This may be a disadvantage at the distal tip of anendoscope where space is limited.

In the implementation shown in FIG. 12B, clock generation is executedusing an on-chip oscillator rather than the off-chip oscillator shown inFIG. 12A. The implementation shown in FIG. 12B provides an advantageousresult in terms of pad 1204 conductor counts. However, such circuits maybe inconsistent and exhibit significant variability from chip to chip.Such circuits are often temperature dependent and can be sensitive toany change in temperature. These drawbacks prevent use in applicationslike video where the framerates needs to be ultra-precise.

The systems, methods, and devices disclosed herein provide means for anon-chip precise clock without additional external components. Onebenefit of this embodiment is that no additional pads or conductors arerequired because existing sensor data output pads and low speed controlprogramming pads are repurposed as an on-chip clock.

FIG. 13 is a circuit diagram of a conventional phase lock loop (PLL)1300. The voltage-controlled delay line (VCDL) clock is compared to theincoming clock. The frequency detector up-pushes and/or down-pushes areissued to the external voltage-controlled oscillator (VCO) depending onthe frequency detector comparison result. The conventional phase lockloop 1300 may dynamically react and adjust to ensure the VCDL clockmatches the input clock.

The systems, methods, and devices disclosed herein created a phase lockloop that overlaps between the image sensor and the camera unit. Thisleverages the communication protocol that already exists between theimage sensor and the camera unit. In an embodiment, the frequencydetector is moved from the phase lock loop to the camera unit. The inputof the frequency detector can be attached to the precise clock providedby the camera unit oscillator. The camera unit oscillator does notincrease sensor pad count because it is in the camera unit. In anembodiment, digital feed-forward and feedback nodes in the phase lockloop may be selected and matches to the feed-forward system node and thefeedback system node. The feed-forward system node is low speed controlprogramming from the camera unit to the image sensor. The feedbacksystem node is pixel data output from the image sensor to the cameraunit.

FIG. 14 is a circuit diagram illustrating clock management and datasequencing between a camera unit 1402 and an image sensor 1404. In anembodiment, the image sensor 1404 is a complementary metal oxidesemiconductor (CMOS) sensor. In an embodiment, the feed-forward node isthe go-fast go-flow signal and is updated using the sensor low speedcontrol programming. The feedback node may be chosen to be themultiplied clock prior to the divider by n. This multiplied frequencymay be used to serialize the pixel data and may be decoded by the CDR inthe camera unit. The result can then be fed bac to the frequencydetector. Such an embodiment does not increase the pad 1406 count or theconductor count.

FIG. 15 is a circuit diagram for clock management and data sequencingbetween a camera unit 1502 and an image sensor 1504. In the embodimentillustrated in FIG. 15, a digital to analog converter (DAC) 1506 is usedinstead of a charge pump. When the DAC 1506 is implemented, the lowspeed control may program a configuration register. This is in contrastwith the push-up/push-down model implemented with a charge pump.

FIG. 16 is a circuit diagram for clock management and data sequencingbetween a camera unit 1602 and an image sensor 1604 without segmentingthe on-chip phase lock loop. The embodiment illustrated in FIG. 16 is anequivalent circuit where the internal phase lock loop remains unchangedand the clock input pad is removed. The input clock signal is providedby a clock generator distributed circuit equivalent to that of FIG. 14.

FIG. 17 is a circuit diagram for clock management and data sequencingbetween a camera unit 1702 and an image sensor 1704. In the embodimentillustrated in FIG. 17, the image sensor 1704 uses a digital to analogconverter (DAC) 1706 rather than a charge pump.

FIG. 18 is a schematic diagram of a process flow 1800 for an algorithmthat may reside in the camera unit. The process flow 1800 may beimplemented in a charge pump system. The process flow 1800 includespowering on the image sensor and performing clock recovery. The processflow 1800 includes performing a frequency counter and determiningwhether the frequency is too high or too low. The process flow 1800includes performing push-ups and push-downs in response to calculationsas illustrated in FIG. 18.

FIG. 19 is a table listing signals and parameters that may be used bythe camera unit for the process flow 1800 illustrated in FIG. 18. Anexample implementation of the process flow 1800 algorithm includes thefollowing. The R_CLK may be compared to the target frequency usingREF_CLK as the method or mode of comparison. If R_CLK is too low, thenPUSH UP may be asserted. If R_CLK is too high, then PUSH DOWN may beasserted. The BIG_LITTLE output may be used based on how far R_CLK isfrom the target frequency. As an example, if a big push represents a 5%change and a little push represents a 1% change in frequency then ifR_CLK is lower than target frequency minus 3%, the block may issue aPUSH UP BIG command. The next time the R_CLK is measured it will beapproximately 2% greater than the target and so the block may issue aPUSH DOWN LITTLE command.

The method of comparing the R_CLK to the target frequency may be asfollows. In an example, if the REF_CLK is 27 MHz, the target is 40 MHzand the R_CLK is 38 MHz, then the block may count the number of R_CLKtransitions over 1 ms (or 27,000 transitions of REF_CLK). It may compareits counter value, now 38,000 to the desired target of 40,000 and issuea PUSH UP BIG command assuming the BIG and LITTLE thresholds are 5% and1%.

FIG. 20 is a schematic diagram of a pattern reconstruction process. Theexample pattern illustrated in FIG. 20 includes Red, Green, Blue, andSpecialty pulses of light that each last a duration of T1. The specialtypulse(s) of light includes one or more of a hyperspectral emission foreliciting a spectral response, a fluorescence excitation emission forexciting a fluorescent reagent, and/or a laser mapping pattern. Invarious embodiments, the pulses of light may be of the same duration orof differing durations. The Red, Green, Blue, and Specialty exposureframes are combined to generate an RGB image with specialty imaging dataoverlaid thereon. The specialty imaging data may include one or more ofa hyperspectral exposure frame, a fluorescence exposure frame, lasermapping data, a three-dimensional topology, tool tracking data, and soforth. A single image frame comprising a red exposure frame, a greenexposure frame, a blue exposure frame, and a specialty exposure framerequires a time period of 4*T1 to be generated. The time durations shownin FIG. 20 are illustrative only and may vary for differentimplementations. In other embodiments, different pulsing schemes may beemployed. For example, embodiments may be based on the timing of eachcolor component or frame (T1) and the reconstructed frame having aperiod twice that of the incoming color frame (2×T1). Different frameswithin the sequence may have different frame periods and the averagecapture rate could be any multiple of the final frame rate.

In an embodiment, the dynamic range of the system is increased byvarying the pixel sensitivities of pixels within the pixel array of theimage sensor. Some pixels may sense reflected electromagnetic radiationat a first sensitivity level, other pixels may sense reflectedelectromagnetic radiation at a second sensitivity level, and so forth.The different pixel sensitivities may be combined to increase thedynamic range provided by the pixel configuration of the image sensor.In an embodiment, adjacent pixels are set at different sensitivitiessuch that each cycle includes data produced by pixels that are more andless sensitive with respect to each other. The dynamic range isincreased when a plurality of sensitivities are recorded in a singlecycle of the pixel array. In an embodiment, wide dynamic range can beachieved by having multiple global TX, each TX firing only on adifferent set of pixels. For example, in global mode, a global TX1signal is firing a set 1 of pixels, a global TX2 signal is firing a set2 of pixel, a global TXn signal is firing a set n of pixels, and soforth.

FIGS. 21A-21C each illustrate a light source 2100 having a plurality ofemitters. The emitters include a first emitter 2102, a second emitter2104, and a third emitter 2106. Additional emitters may be included, asdiscussed further below. The emitters 2102, 2104, and 2106 may includeone or more laser emitters that emit light having different wavelengths.For example, the first emitter 2102 may emit a wavelength that isconsistent with a blue laser, the second emitter 2104 may emit awavelength that is consistent with a green laser, and the third emitter2106 may emit a wavelength that is consistent with a red laser. Forexample, the first emitter 2102 may include one or more blue lasers, thesecond emitter 2104 may include one or more green lasers, and the thirdemitter 2106 may include one or more red lasers. The emitters 2102,2104, 2106 emit laser beams toward a collection region 2108, which maybe the location of a waveguide, lens, or other optical component forcollecting and/or providing light to a waveguide, such as the jumperwaveguide 206 or lumen waveguide 210 of FIG. 2.

In an implementation, the emitters 2102, 2104, and 2106 emithyperspectral wavelengths of electromagnetic radiation. Certainhyperspectral wavelengths may pierce through tissue and enable a medicalpractitioner to “see through” tissues in the foreground to identifychemical processes, structures, compounds, biological processes, and soforth that are located behind the tissues in the foreground. Thehyperspectral wavelengths may be specifically selected to identify aspecific disease, tissue condition, biological process, chemicalprocess, type of tissue, and so forth that is known to have a certainspectral response.

In an implementation where a patient has been administered a reagent ordye to aid in the identification of certain tissues, structures,chemical reactions, biological processes, and so forth, the emitters2102, 2104, and 2106 may emit wavelength(s) for fluorescing the reagentsor dyes. Such wavelength(s) may be determined based on the reagents ordyes administered to the patient. In such an embodiment, the emittersmay need to be highly precise for emitting desired wavelength(s) tofluoresce or activate certain reagents or dyes.

In an implementation, the emitters 2102, 2104, and 2106 emit a lasermapping pattern for mapping a topology of a scene and/or for calculatingdimensions and distances between objects in the scene. In an embodiment,the endoscopic imaging system is used in conjunction with multiple toolssuch as scalpels, retractors, forceps, and so forth. In such anembodiment, each of the emitters 2102, 2104, and 2106 may emit a lasermapping pattern such that a laser mapping pattern is projected on toeach tool individually. In such an embodiment, the laser mapping datafor each of the tools can be analyzed to identify distances between thetools and other objects in the scene.

In the embodiment of FIG. 21B, the emitters 2102, 2104, 2106 eachdeliver laser light to the collection region 2108 at different angles.The variation in angle can lead to variations where electromagneticenergy is located in an output waveguide. For example, if the lightpasses immediately into a fiber bundle (glass or plastic) at thecollection region 2108, the varying angles may cause different amountsof light to enter different fibers. For example, the angle may result inintensity variations across the collection region 2108. Furthermore,light from the different emitters may not be homogenously mixed so somefibers may receive different amounts of light of different colors.Variation in the color or intensity of light in different fibers canlead to non-optimal illumination of a scene. For example, variations indelivered light or light intensities may result at the scene andcaptured images.

In one embodiment, an intervening optical element may be placed betweena fiber bundle and the emitters 2102, 2104, 2106 to mix the differentcolors (wavelengths) of light before entry into the fibers or otherwaveguide. Example intervening optical elements include a diffuser,mixing rod, one or more lenses, or other optical components that mix thelight so that a given fiber receive a same amount of each color(wavelength). For example, each fiber in the fiber bundle may have asame color. This mixing may lead to the same color in each fiber butmay, in some embodiments, still result in different total brightnessdelivered to different fibers. In one embodiment, the interveningoptical element may also spread out or even out the light over thecollection region so that each fiber carries the same total amount oflight (e.g., the light may be spread out in a top hat profile). Adiffuser or mixing rod may lead to loss of light.

Although the collection region 2108 is represented as a physicalcomponent in FIG. 21A, the collection region 2108 may simply be a regionwhere light from the emitters 2102, 2104, and 2106 is delivered. In somecases, the collection region 2108 may include an optical component suchas a diffuser, mixing rod, lens, or any other intervening opticalcomponent between the emitters 2102, 2104, 2106 and an output waveguide.

FIG. 21C illustrates an embodiment of a light source 2100 with emitters2102, 2104, 2106 that provide light to the collection region 2108 at thesame or substantially same angle. The light is provided at an anglesubstantially perpendicular to the collection region 2108. The lightsource 2100 includes a plurality of dichroic mirrors including a firstdichroic mirror 2110, a second dichroic mirror 2112, and a thirddichroic mirror 2114. The dichroic mirrors 2110, 2112, 2114 includemirrors that reflect a first wavelength of light but transmit (or aretransparent to) a second wavelength of light. For example, the thirddichroic mirror 2114 may reflect blue laser light provided by the thirdemitter, while being transparent to the red and green light provided bythe first emitter 2102 and the second emitter 2104, respectively. Thesecond dichroic mirror 2112 may be transparent to red light from thefirst emitter 2102, but reflective to green light from the secondemitter 2104. If other colors or wavelengths are included dichroicmirrors may be selected to reflect light corresponding to at least oneemitter and be transparent to other emitters. For example, the thirddichroic mirror 2114 reflect the light form the third emitter 2106 butis to emitters “behind” it, such as the first emitter 2102 and thesecond emitter 2104. In embodiments where tens or hundreds of emittersare present, each dichroic mirror may be reflective to a correspondingemitter and emitters in front of it while being transparent to emittersbehind it. This may allow for tens or hundreds of emitters to emitelectromagnetic energy to the collection region 2108 at a substantiallysame angle.

Because the dichroic mirrors allow other wavelengths to transmit or passthrough, each of the wavelengths may arrive at the collection region2108 from a same angle and/or with the same center or focal point.Providing light from the same angle and/or same focal/center point cansignificantly improve reception and color mixing at the collectionregion 2108. For example, a specific fiber may receive the differentcolors in the same proportions they were transmitted/reflected by theemitters 2102, 2104, 2106 and mirrors 2110, 2112, 2114. Light mixing maybe significantly improved at the collection region compared to theembodiment of FIG. 21B. In one embodiment, any optical componentsdiscussed herein may be used at the collection region 2108 to collectlight prior to providing it to a fiber or fiber bundle.

FIG. 21C illustrates an embodiment of a light source 2100 with emitters2102, 2104, 2106 that also provide light to the collection region 2108at the same or substantially same angle. However, the light incident onthe collection region 2108 is offset from being perpendicular. Angle2116 indicates the angle offset from perpendicular. In one embodiment,the laser emitters 2102, 2104, 2106 may have cross sectional intensityprofiles that are Gaussian. As discussed previously, improveddistribution of light energy between fibers may be accomplished bycreating a more flat or top-hat shaped intensity profile. In oneembodiment, as the angle 2116 is increased, the intensity across thecollection region 2108 approaches a top hat profile. For example, atop-hat profile may be approximated even with a non-flat output beam byincreasing the angle 2116 until the profile is sufficiently flat. Thetop hat profile may also be accomplished using one or more lenses,diffusers, mixing rods, or any other intervening optical componentbetween the emitters 2102, 2104, 2106 and an output waveguide, fiber, orfiber optic bundle.

FIG. 22 is a schematic diagram illustrating a single optical fiber 2202outputting via a diffuser 2204 at an output. In one embodiment, theoptical fiber 2202 has a diameter of 500 microns, a numerical apertureof 0.65, and emits a light cone 2206 of about 70 or 80 degrees without adiffuser 2204. With the diffuser 2204, the light cone 2206 may have anangle of about 110 or 120 degrees. The light cone 2206 may be a majorityof where all light goes and is evenly distributed. The diffuser 2204 mayallow for more even distribution of electromagnetic energy of a sceneobserved by an image sensor.

In one embodiment, the lumen waveguide 210 includes a single plastic orglass optical fiber of about 500 microns. The plastic fiber may be lowcost, but the width may allow the fiber to carry a sufficient amount oflight to a scene, with coupling, diffusion, or other losses. Forexample, smaller fibers may not be able to carry as much light or poweras a larger fiber. The lumen waveguide 210 may include a single or aplurality of optical fibers. The lumen waveguide 210 may receive lightdirectly from the light source or via a jumper waveguide. A diffuser maybe used to broaden the light output 206 for a desired field of view ofthe image sensor 214 or other optical components.

Although three emitters are shown in FIGS. 21A-21C, emitters numberingfrom one into the hundreds or more may be used in some embodiments. Theemitters may have different wavelengths or spectrums of light that theyemit, and which may be used to contiguously cover a desired portion ofthe electromagnetic spectrum (e.g., the visible spectrum as well asinfrared and ultraviolet spectrums). The emitters may be configured toemit visible light such as red light, green light, and blue light, andmay further be configured to emit hyperspectral emissions ofelectromagnetic radiation, fluorescence excitation wavelengths forfluorescing a reagent, and/or laser mapping patterns for calculatingparameters and distances between objects in a scene.

FIG. 23 illustrates a portion of the electromagnetic spectrum 2300divided into twenty different sub-spectrums. The number of sub-spectrumsis illustrative only. In at least one embodiment, the spectrum 2300 maybe divided into hundreds of sub-spectrums, each with a small waveband.The spectrum may extend from the infrared spectrum 2302, through thevisible spectrum 2304, and into the ultraviolet spectrum 2306. Thesub-spectrums each have a waveband 2308 that covers a portion of thespectrum 2300. Each waveband may be defined by an upper wavelength and alower wavelength.

Hyperspectral imaging includes imaging information from across theelectromagnetic spectrum 2300. A hyperspectral pulse of electromagneticradiation may include a plurality of sub-pulses spanning one or moreportions of the electromagnetic spectrum 2300 or the entirety of theelectromagnetic spectrum 2300. A hyperspectral pulse of electromagneticradiation may include a single partition of wavelengths ofelectromagnetic radiation. A resulting hyperspectral exposure frameincludes information sensed by the pixel array subsequent to ahyperspectral pulse of electromagnetic radiation. Therefore, ahyperspectral exposure frame may include data for any suitable partitionof the electromagnetic spectrum 2300 and may include multiple exposureframes for multiple partitions of the electromagnetic spectrum 2300. Inan embodiment, a hyperspectral exposure frame includes multiplehyperspectral exposure frames such that the combined hyperspectralexposure frame comprises data for the entirety of the electromagneticspectrum 2300.

In one embodiment, at least one emitter (such as a laser emitter) isincluded in a light source (such as the light sources 202, 2100) foreach sub-spectrum to provide complete and contiguous coverage of thewhole spectrum 2300. For example, a light source for providing coverageof the illustrated sub-spectrums may include at least 20 differentemitters, at least one for each sub-spectrum. In one embodiment, eachemitter covers a spectrum covering 40 nanometers. For example, oneemitter may emit light within a waveband from 500 nm to 540 nm whileanother emitter may emit light within a waveband from 540 nm to 580 nm.In another embodiment, emitters may cover other sizes of wavebands,depending on the types of emitters available or the imaging needs. Forexample, a plurality of emitters may include a first emitter that coversa waveband from 500 to 540 nm, a second emitter that covers a wavebandfrom 540 nm to 640 nm, and a third emitter that covers a waveband from640 nm to 650 nm. Each emitter may cover a different slice of theelectromagnetic spectrum ranging from far infrared, mid infrared, nearinfrared, visible light, near ultraviolet and/or extreme ultraviolet. Insome cases, a plurality of emitters of the same type or wavelength maybe included to provide sufficient output power for imaging. The numberof emitters needed for a specific waveband may depend on the sensitivityof a monochrome sensor to the waveband and/or the power outputcapability of emitters in that waveband.

The waveband widths and coverage provided by the emitters may beselected to provide any desired combination of spectrums. For example,contiguous coverage of a spectrum using very small waveband widths(e.g., 10 nm or less) may allow for highly selective hyperspectraland/or fluorescence imaging. The waveband widths may allow forselectively emitting the excitation wavelength(s) for one or moreparticular fluorescent reagents. Additionally, the waveband widths mayallow for selectively emitting certain partitions of hyperspectralelectromagnetic radiation for identifying specific structures, chemicalprocesses, tissues, biological processes, and so forth. Because thewavelengths come from emitters which can be selectively activated,extreme flexibility for fluorescing one or more specific fluorescentreagents during an examination can be achieved. Additionally, extremeflexibility for identifying one or more objects or processes by way ofhyperspectral imaging can be achieved. Thus, much more fluorescenceand/or hyperspectral information may be achieved in less time and withina single examination which would have required multiple examinations,delays because of the administration of dyes or stains, or the like.

FIG. 24 is a schematic diagram illustrating a timing diagram 2400 foremission and readout for generating an image. The solid line representsreadout (peaks 2402) and blanking periods (valleys) for capturing aseries of exposure frames 2404-2414. The series of exposure frames2404-2414 may include a repeating series of exposure frames which may beused for generating laser mapping, hyperspectral, and/or fluorescencedata that may be overlaid on an RGB video stream. In an embodiment, asingle image frame comprises information from multiple exposure frames,wherein one exposure frame includes red image data, another exposureframe includes green image data, and another exposure frame includesblue image data. Additionally, the single image frame may include one ormore of hyperspectral image data, fluorescence image data, and lasermapping data. The multiple exposure frames are combined to produce thesingle image frame. In an embodiment, the single image frame is an RGBimage with fluorescence imaging data overlaid on the RGB image. Theseries of exposure frames include a first exposure frame 2404, a secondexposure frame 2406, a third exposure frame 2408, a fourth exposureframe 2410, a fifth exposure frame 2412, and an Nth exposure frame 2426.

Additionally, the hyperspectral image data, the fluorescence image data,and the laser mapping data can be used in combination to identifycritical tissues or structures and further to measure the dimensions ofthose critical tissues or structures. For example, the hyperspectralimage data may be provided to a corresponding system to identify certaincritical structures in a body such as a nerve, ureter, blood vessel,cancerous tissue, and so forth. The location and identification of thecritical structures may be received from the corresponding system andmay further be used to generate topology of the critical structuresusing the laser mapping data. For example, a corresponding systemdetermines the location of a cancerous tumor based on hyperspectralimaging data. Because the location of the cancerous tumor is known basedon the hyperspectral imaging data, the topology and distances of thecancerous tumor may then be calculated based on laser mapping data. Thisexample may also apply when a cancerous tumor or other structure isidentified based on fluorescence imaging data.

In one embodiment, each exposure frame is generated based on at leastone pulse of electromagnetic energy. The pulse of electromagnetic energyis reflected and detected by an image sensor and then read out in asubsequent readout (2402). Thus, each blanking period and readoutresults in an exposure frame for a specific spectrum of electromagneticenergy. For example, the first exposure frame 2404 may be generatedbased on a spectrum of a first one or more pulses 2416, a secondexposure frame 2406 may be generated based on a spectrum of a second oneor more pulses 2418, a third exposure frame 2408 may be generated basedon a spectrum of a third one or more pulses 2420, a fourth exposureframe 2410 may be generated based on a spectrum of a fourth one or morepulses 2422, a fifth exposure frame 2412 may be generated based on aspectrum of a fifth one or more pulses 2424, and an Nth exposure frame2426 may be generated based on a spectrum of an Nth one or more pulses2426.

The pulses 2416-2426 may include energy from a single emitter or from acombination of two or more emitters. For example, the spectrum includedin a single readout period or within the plurality of exposure frames2404-2414 may be selected for a desired examination or detection of aspecific tissue or condition. According to one embodiment, one or morepulses may include visible spectrum light for generating an RGB or blackand white image while one or more additional pulses are emitted to sensea spectral response to a hyperspectral wavelength of electromagneticradiation. For example, pulse 2416 may include red light, pulse 2418 mayinclude blue light, and pulse 2420 may include green light while theremaining pulses 2422-2426 may include wavelengths and spectrums fordetecting a specific tissue type, fluorescing a reagent, and/or mappingthe topology of the scene. As a further example, pulses for a singlereadout period include a spectrum generated from multiple differentemitters (e.g., different slices of the electromagnetic spectrum) thatcan be used to detect a specific tissue type. For example, if thecombination of wavelengths results in a pixel having a value exceedingor falling below a threshold, that pixel may be classified ascorresponding to a specific type of tissue. Each frame may be used tofurther narrow the type of tissue that is present at that pixel (e.g.,and each pixel in the image) to provide a very specific classificationof the tissue and/or a state of the tissue (diseased/healthy) based on aspectral response of the tissue and/or whether a fluorescent reagent ispresent at the tissue.

The plurality of frames 2404-2414 is shown having varying lengths inreadout periods and pulses having different lengths or intensities. Theblanking period, pulse length or intensity, or the like may be selectedbased on the sensitivity of a monochromatic sensor to the specificwavelength, the power output capability of the emitter(s), and/or thecarrying capacity of the waveguide.

In one embodiment, dual image sensors may be used to obtainthree-dimensional images or video feeds. A three-dimensional examinationmay allow for improved understanding of a three-dimensional structure ofthe examined region as well as a mapping of the different tissue ormaterial types within the region.

In an example implementation, a fluorescent reagent is provided to apatient, and the fluorescent reagent is configured to adhere tocancerous cells. The fluorescent reagent is known to fluoresce whenradiated with a specific partition of electromagnetic radiation. Therelaxation wavelength of the fluorescent reagent is also known. In theexample implementation, the patient is imaged with an endoscopic imagingsystem as discussed herein. The endoscopic imaging system pulsespartitions of red, green, and blue wavelengths of light to generate anRGB video stream of the interior of the patient's body. Additionally,the endoscopic imaging system pulses the excitation wavelength ofelectromagnetic radiation for the fluorescent reagent that wasadministered to the patient. In the example, the patient has cancerouscells and the fluorescent reagent has adhered to the cancerous cells.When the endoscopic imaging system pulses the excitation wavelength forthe fluorescent reagent, the fluorescent reagent will fluoresce and emita relaxation wavelength. If the cancerous cells are present in the scenebeing imaged by the endoscopic imaging system, then the fluorescentreagent will also be present in the scene and will emit its relaxationwavelength after fluorescing due to the emission of the excitationwavelength. The endoscopic imaging system senses the relaxationwavelength of the fluorescent reagent and thereby senses the presence ofthe fluorescent reagent in the scene. Because the fluorescent reagent isknown to adhere to cancerous cells, the presence of the fluorescentreagent further indicates the presence of cancerous cells within thescene. The endoscopic imaging system thereby identifies the location ofcancerous cells within the scene. The endoscopic imaging system mayfurther emit a laser mapping pulsing scheme for generating a topology ofthe scene and calculating dimensions for objects within the scene. Thelocation of the cancerous cells (as identified by the fluorescenceimaging data) may be combined with the topology and dimensionsinformation calculated based on the laser mapping data. Therefore, theprecise location, size, dimensions, and topology of the cancerous cellsmay be identified. This information may be provided to a medicalpractitioner to aid in excising the cancerous cells. Additionally, thisinformation may be provided to a robotic surgical system to enable thesurgical system to excise the cancerous cells.

In a further example implementation, a patient is imaged with anendoscopic imaging system to identify quantitative diagnosticinformation about the patient's tissue pathology. In the example, thepatient is suspected or known to suffer from a disease that can betracked with hyperspectral imaging to observe the progression of thedisease in the patient's tissue. The endoscopic imaging system pulsespartitions of red, green, and blue wavelengths of light to generate anRGB video stream of the interior of the patient's body. Additionally,the endoscopic imaging system pulses one or more hyperspectralwavelengths of light that permit the system to “see through” sometissues and generate imaging of the tissue that is affected by thedisease. The endoscopic imaging system senses the reflectedhyperspectral electromagnetic radiation to generate hyperspectralimaging data of the diseased tissue, and thereby identifies the locationof the diseased tissue within the patient's body. The endoscopic imagingsystem may further emit a laser mapping pulsing scheme for generating atopology of the scene and calculating dimensions of objects within thescene. The location of the diseased tissue (as identified by thehyperspectral imaging data) may be combined with the topology anddimensions information that is calculated with the laser mapping data.Therefore, the precise location, size, dimensions, and topology of thediseased tissue can be identified. This information may be provided to amedical practitioner to aid in excising, imaging, or studying thediseased tissue. Additionally, this information may be provided to arobotic surgical system to enable the surgical system to excise thediseased tissue.

FIG. 25 is a schematic diagram of an imaging system 2500 having a singlecut filter. The system 2500 includes an endoscope 2506 or other suitableimaging device having a light source 2508 for use in a light deficientenvironment. The endoscope 2506 includes an image sensor 2504 and afilter 2502 for filtering out unwanted wavelengths of light or otherelectromagnetic radiation before reaching the image sensor 2504. Thelight source 2508 transmits light that may illuminate the surface 2512in a light deficient environment such as a body cavity. The light 2510is reflected off the surface 2512 and passes through the filter 2502before hitting the image sensor 2504.

The filter 2502 may be used in an implementation where a fluorescentreagent or dye has been administered. In such an embodiment, the lightsource 2508 emits the excitation wavelength for fluorescing thefluorescent reagent or dye. Commonly, the relaxation wavelength emittedby the fluorescent reagent or dye will be of a different wavelength thanthe excitation wavelength. The filter 2502 may be selected to filter outthe excitation wavelength and permit only the relaxation wavelength topass through the filter and be sensed by the image sensor 2504.

In one embodiment, the filter 2502 is configured to filter out anexcitation wavelength of electromagnetic radiation that causes a reagentor dye to fluoresce such that only the expected relaxation wavelength ofthe fluoresced reagent or dye is permitted to pass through the filter2502 and reach the image sensor 2504. In an embodiment, the filter 2502filters out at least a fluorescent reagent excitation wavelength between770 nm and 790 nm. In an embodiment, the filter 2502 filters out atleast a fluorescent reagent excitation wavelength between 795 nm and 815nm. In an embodiment, the filter 2502 filters out at least a fluorescentreagent excitation wavelength between 770 nm and 790 nm and between 795nm and 815 nm. In these embodiments, the filter 2502 filters out theexcitation wavelength of the reagent and permits only the relaxationwavelength of the fluoresced reagent to be read by the image sensor2504. The image sensor 2504 may be a wavelength-agnostic image sensorand the filter 2502 may be configured to permit the image sensor 2504 toonly receive the relaxation wavelength of the fluoresced reagent and notreceive the emitted excitation wavelength for the reagent. The datadetermined by the image sensor 2504 may then indicate a presence of acritical body structure, tissue, biological process, or chemical processas determined by a location of the reagent or dye.

The filter 2502 may further be used in an implementation where afluorescent reagent or dye has not been administered. The filter 2502may be selected to permit wavelengths corresponding to a desiredspectral response to pass through and be read by the image sensor 2504.The image sensor 2504 may be a monochromatic image sensor such thatpixels of the captured image that exceed a threshold or fall below athreshold may be characterized as corresponding to a certain spectralresponse or fluorescence emission. The spectral response or fluorescenceemission, as determined by the pixels captured by the image sensor 2504,may indicate the presence of a certain body tissue or structure, acertain condition, a certain chemical process, and so forth.

FIG. 26 is a schematic diagram of an imaging system 2600 having multiplecut filters. The system 2600 includes an endoscope 2606 or othersuitable imaging device having a light source 2608 for use in a lightdeficient environment. The endoscope 2606 includes an image sensor 2604and two filters 2602 a, 2602 b. It should be appreciated that inalternative embodiments, the system 2600 may include any number offilters, and the number of filters and the type of filters may beselected for a certain purpose e.g., for gathering imaging informationof a particular body tissue, body condition, chemical process, and soforth. The filters 2602 a, 2602 b are configured for preventing unwantedwavelengths of light or other electromagnetic radiation from beingsensed by the image sensor 2604. The filters 2602 a, 2602 b may beconfigured to filter out unwanted wavelengths from white light or otherelectromagnetic radiation that may be emitted by the light source 2608.

Further to the disclosure with respect to FIG. 25, the filters 2602 a,2602 b may be used in an implementation where a fluorescent reagent ordye has been administered. The filters 2602 a, 2602 b may be configuredfor blocking an emitted excitation wavelength for the reagent or dye andpermitting the image sensor 2604 to only read the relaxation wavelengthof the reagent or dye. Further, the filters 2602 a, 2602 b may be usedin an implementation where a fluorescent reagent or dye has not beenadministered. In such an implementation, the filters 2602 a, 2602 b maybe selected to permit wavelengths corresponding to a desired spectralresponse to pass through and be read by the image sensor 2604.

The multiple filters 2602 a, 2602 b may each be configured for filteringout a different range of wavelengths of the electromagnetic spectrum.For example, one filter may be configured for filtering out wavelengthslonger than a desired wavelength range and the additional filter may beconfigured for filtering out wavelengths shorter than the desiredwavelength range. The combination of the two or more filters may resultin only a certain wavelength or band of wavelengths being read by theimage sensor 2604.

In an embodiment, the filters 2602 a, 2602 b are customized such thatelectromagnetic radiation between 513 nm and 545 nm contacts the imagesensor 2604. In an embodiment, the filters 2602 a, 2602 b are customizedsuch that electromagnetic radiation between 565 nm and 585 nm contactsthe image sensor 2604. In an embodiment, the filters 2602 a, 2602 b arecustomized such that electromagnetic radiation between 900 nm and 1000nm contacts the image sensor 2604. In an embodiment, the filters 2602 a,2602 b are customized such that electromagnetic radiation between 425 nmand 475 nm contacts the image sensor 2604. In an embodiment, the filters2602 a, 2602 b are customized such that electromagnetic radiationbetween 520 nm and 545 nm contacts the image sensor 2604. In anembodiment, the filters 2602 a, 2602 b are customized such thatelectromagnetic radiation between 625 nm and 645 nm contacts the imagesensor 2604. In an embodiment, the filters 2602 a, 2602 b are customizedsuch that electromagnetic radiation between 760 nm and 795 nm contactsthe image sensor 2604. In an embodiment, the filters 2602 a, 2602 b arecustomized such that electromagnetic radiation between 795 nm and 815 nmcontacts the image sensor 2604. In an embodiment, the filters 2602 a,2602 b are customized such that electromagnetic radiation between 370 nmand 420 nm contacts the image sensor 2604. In an embodiment, the filters2602 a, 2602 b are customized such that electromagnetic radiationbetween 600 nm and 670 nm contacts the image sensor 2604. In anembodiment, the filters 2602 a, 2602 b are configured for permittingonly a certain fluorescence relaxation emission to pass through thefilters 2602 a, 2602 b and contact the image sensor 2604. In anembodiment, a first filter blocks electromagnetic radiation having awavelength from about 770 nm to about 790 nm, and a second filter blockselectromagnetic radiation having a wavelength from about 795 nm to about815 nm.

In an embodiment, the system 2600 includes multiple image sensors 2604and may particularly include two image sensors for use in generating athree-dimensional image. The image sensor(s) 2604 may becolor/wavelength agnostic and configured for reading any wavelength ofelectromagnetic radiation that is reflected off the surface 2612. In anembodiment, the image sensors 2604 are each color dependent orwavelength dependent and configured for reading electromagneticradiation of a particular wavelength that is reflected off the surface2612 and back to the image sensors 2604. Alternatively, the image sensor2604 may include a single image sensor with a plurality of differentpixel sensors configured for reading different wavelengths or colors oflight, such as a Bayer filter color filter array. Alternatively, theimage sensor 2604 may include one or more color agnostic image sensorsthat may be configured for reading different wavelengths ofelectromagnetic radiation according to a pulsing schedule such as thoseillustrated in FIGS. 5-7E, for example.

FIG. 27 is a schematic diagram illustrating a system 2700 for mapping asurface and/or tracking an object in a light deficient environmentthrough laser mapping imaging. In an embodiment, an endoscope 2706 in alight deficient environment pulses a grid array 2706 (may be referred toas a laser map pattern) on a surface 2704. The grid array 2706 includesvertical hashing 2708 and horizontal hashing 2710 in one embodiment asillustrated in FIG. 27. It should be appreciated the grid array 2706 mayinclude any suitable array for mapping a surface 2704, including, forexample, a raster grid of discrete points, an occupancy grid map, a dotarray, and so forth. Additionally, the endoscope 2706 may pulse multiplegrid arrays 2706 and may, for example, pulse one or more individual gridarrays on each of a plurality of objects or structures within the lightdeficient environment.

In an embodiment, the system 2700 pulses a grid array 2706 that may beused for mapping a three-dimensional topology of a surface and/ortracking a location of an object such as a tool or another device in alight deficient environment. In an embodiment, the system 2700 providesdata to a third-party system or computer algorithm for determiningsurface dimensions and configurations by way of light detection andranging (LIDAR) mapping. The system 2700 may pulse any suitablewavelength of light or electromagnetic radiation in the grid array 2706,including, for example, ultraviolet light, visible, light, and/orinfrared or near infrared light. The surface 2704 and/or objects withinthe environment may be mapped and tracked at very high resolution andwith very high accuracy and precision.

In an embodiment, the system 2700 includes an imaging device having atube, one or more image sensors, and a lens assembly having an opticalelement corresponding to the one or more image sensors. The system 2700may include a light engine having an emitter generating one or morepulses of electromagnetic radiation and a lumen transmitting the one ormore pulses of electromagnetic radiation to a distal tip of an endoscope within a light deficient environment such as a body cavity. In anembodiment, at least a portion of the one or more pulses ofelectromagnetic radiation includes a laser map pattern that is emittedonto a surface within the light deficient environment, such as a surfaceof body tissue and/or a surface of tools or other devices within thebody cavity. The endoscope 2706 may include a two-dimensional,three-dimensional, or n-dimensional camera for mapping and/or trackingthe surface, dimensions, and configurations within the light deficientenvironment.

In an embodiment, the system 2700 includes a processor for determining adistance of an endoscope or tool from an object such as the surface2704. The processor may further determine an angle between the endoscopeor tool and the object. The processor may further determine surface areainformation about the object, including for example, the size ofsurgical tools, the size of structures, the size of anatomicalstructures, location information, and other positional data and metrics.The system 2700 may include one or more image sensors that provide imagedata that is output to a control system for determining a distance of anendoscope or tool to an object such as the surface 2704. The imagesensors may output information to a control system for determining anangle between the endoscope or tool to the object. Additionally, theimage sensors may output information to a control system for determiningsurface area information about the object, the size of surgical tools,size of structures, size of anatomical structures, location information,and other positional data and metrics.

In an embodiment, the grid array 2706 is pulsed by an emitter of theendoscope 2706 at a sufficient speed such that the grid array 2706 isnot visible to a user. In various implementations, it may be distractingto a user to see the grid array 2706 during an endoscopic imagingprocedure and/or endoscopic surgical procedure. The grid array 2706 maybe pulsed for sufficiently brief periods such that the grid array 2706cannot be detected by a human eye. In an alternative embodiment, theendoscope 2706 pulses the grid array 2706 at a sufficient recurringfrequency such that the grid array 2706 may be viewed by a user. In suchan embodiment, the grid array 2706 may be overlaid on an image of thesurface 2704 on a display. The grid array 2706 may be overlaid on ablack-and-white or RGB image of the surface 2704 such that the gridarray 2706 may be visible by a user during use of the system 2700. Auser of the system 2700 may indicate whether the grid array 2706 shouldbe overlaid on an image of the surface 2704 and/or whether the gridarray 2706 should be visible to the user. The system 2700 may include adisplay that provides real-time measurements of a distance from theendoscope 2706 to the surface 2704 or another object within the lightdeficient environment. The display may further provide real-time surfacearea information about the surface 2704 and/or any objects, structures,or tools within the light deficient environment. The accuracy of themeasurements may be accurate to less than one millimeter.

In an embodiment, the system 2700 pulses a plurality of grid arrays2706. In an embodiment, each of the plurality of grid arrays 2706corresponds to a tool or other device present within the light deficientenvironment. The precise locations and parameters of each of the toolsand other devices may be tracked by pulsing and sensing the plurality ofgrid arrays 2706. The information generated by sensing the reflectedgrid arrays 2706 can be assessed to identify relative locations of thetools and other devices within the light deficient environment.

The endoscope 2706 may pulse electromagnetic radiation according to apulsing schedule such as those illustrated herein that may furtherinclude pulsing of the grid array 2706 along with pulsing Red, Green,and Blue light for generating an RGB image and further generating a gridarray 2706 that may be overlaid on the RGB image and/or used for mappingand tracking the surface 2704 and objects within the light deficientenvironment. The grid array 2706 may additionally be pulsed inconjunction with hyperspectral or fluorescent excitation wavelengths ofelectromagnetic radiation. The data from each of the RGB imaging, thelaser mapping imaging, the hyperspectral imaging, and the fluorescenceimaging may be combined to identify the locations, dimensions, andsurface topology of critical structures in a body.

In an embodiment, the endoscope 2706 includes one or more color agnosticimage sensors. In an embodiment, the endoscope 2706 includes two coloragnostic image sensors for generating a three-dimensional image or mapof the light deficient environment. The image sensors may generate anRGB image of the light deficient environment according to a pulsingschedule as disclosed herein. Additionally, the image sensors maydetermine data for mapping the light deficient environment and trackingone or more objects within the light deficient environment based on datadetermined when the grid array 2706 is pulsed. Additionally, the imagesensors may determine spectral or hyperspectral data along withfluorescence imaging data according to a pulsing schedule that may bemodified by a user to suit the particular needs of an imaging procedure.In an embodiment, a pulsing schedule includes Red, Green, and Bluepulses along with pulsing of a grid array 2706 and/or pulsing forgenerating hyperspectral image data and/or fluorescence image data. Invarious implementations, the pulsing schedule may include any suitablecombination of pulses of electromagnetic radiation according to theneeds of a user. The recurring frequency of the different wavelengths ofelectromagnetic radiation may be determined based on, for example, theenergy of a certain pulse, the needs of the user, whether certain data(for example, hyperspectral data and/or fluorescence imaging data) needsto be continuously updated or may be updated less frequently, and soforth.

The pulsing schedule may be modified in any suitable manner, and certainpulses of electromagnetic radiation may be repeated at any suitablefrequency, according to the needs of a user or computer-implementedprogram for a certain imaging procedure. For example, in an embodimentwhere surface tracking data generated based on the grid array 2706 isprovided to a computer-implemented program for use in, for example, arobotic surgical procedure, the grid array 2706 may be pulsed morefrequently than if the surface tracking data is provided to a user whois visualizing the scene during the imaging procedure. In such anembodiment where the surface tracking data is used for a roboticsurgical procedure, the surface tracking data may need to be updatedmore frequently or may need to be exceedingly accurate such that thecomputer-implemented program may execute the robotic surgical procedurewith precision and accuracy.

In an embodiment, the system 2700 is configured to generate an occupancygrid map comprising an array of cells divided into grids. The system2700 is configured to store height values for each of the respectivegrid cells to determine a surface mapping of a three-dimensionalenvironment in a light deficient environment.

FIGS. 28A and 28B illustrate a perspective view and a side view,respectively, of an implementation of a monolithic sensor 2800 having aplurality of pixel arrays for producing a three-dimensional image inaccordance with the teachings and principles of the disclosure. Such animplementation may be desirable for three-dimensional image capture,wherein the two-pixel arrays 2802 and 2804 may be offset during use. Inanother implementation, a first pixel array 2802 and a second pixelarray 2804 may be dedicated to receiving a predetermined range of wavelengths of electromagnetic radiation, wherein the first pixel array isdedicated to a different range of wavelength electromagnetic radiationthan the second pixel array.

FIGS. 29A and 29B illustrate a perspective view and a side view,respectively, of an implementation of an imaging sensor 2900 built on aplurality of substrates. As illustrated, a plurality of pixel columns2904 forming the pixel array are located on the first substrate 2902 anda plurality of circuit columns 2908 are located on a second substrate2906. Also illustrated in the figure are the electrical connection andcommunication between one column of pixels to its associated orcorresponding column of circuitry. In one implementation, an imagesensor, which might otherwise be manufactured with its pixel array andsupporting circuitry on a single, monolithic substrate/chip, may havethe pixel array separated from all or a majority of the supportingcircuitry. The disclosure may use at least two substrates/chips, whichwill be stacked together using three-dimensional stacking technology.The first 2902 of the 2902 substrates/chips may be processed using animage CMOS process. The first substrate/chip 2902 may be comprisedeither of a pixel array exclusively or a pixel array surrounded bylimited circuitry. The second or subsequent substrate/chip 2906 may beprocessed using any process and does not have to be from an image CMOSprocess. The second substrate/chip 2906 may be, but is not limited to, ahighly dense digital process to integrate a variety and number offunctions in a very limited space or area on the substrate/chip, or amixed-mode or analog process to integrate for example precise analogfunctions, or a RF process to implement wireless capability, or MEMS(Micro-Electro-Mechanical Systems) to integrate MEMS devices. The imageCMOS substrate/chip 2902 may be stacked with the second or subsequentsubstrate/chip 2906 using any three-dimensional technique. The secondsubstrate/chip 2906 may support most, or a majority, of the circuitrythat would have otherwise been implemented in the first image CMOS chip2902 (if implemented on a monolithic substrate/chip) as peripheralcircuits and therefore have increased the overall system area whilekeeping the pixel array size constant and optimized to the fullestextent possible. The electrical connection between the twosubstrates/chips may be done through interconnects, which may be wirebonds, bump and/or TSV (Through Silicon Via).

FIGS. 30A and 30B illustrate a perspective view and a side view,respectively, of an implementation of an imaging sensor 3000 having aplurality of pixel arrays for producing a three-dimensional image. Thethree-dimensional image sensor may be built on a plurality of substratesand may comprise the plurality of pixel arrays and other associatedcircuitry, wherein a plurality of pixel columns 3004 a forming the firstpixel array and a plurality of pixel columns 3004 b forming a secondpixel array are located on respective substrates 3002 a and 3002 b,respectively, and a plurality of circuit columns 3008 a and 3008 b arelocated on a separate substrate 3006. Also illustrated are theelectrical connections and communications between columns of pixels toassociated or corresponding column of circuitry.

The plurality of pixel arrays may sense information simultaneously andthe information from the plurality of pixel arrays may be combined togenerate a three-dimensional image. In an embodiment, an endoscopicimaging system includes two or more pixel arrays that can be deployed togenerate three-dimensional imaging. The endoscopic imaging system mayinclude an emitter for emitting pulses of electromagnetic radiationduring a blanking period of the pixel arrays. The pixel arrays may besynced such that the optical black pixels are read (i.e., the blankingperiod occurs) at the same time for the two or more pixel arrays. Theemitter may emit pulses of electromagnetic radiation for charging eachof the two or more pixel arrays. The two or more pixel arrays may readtheir respective charged pixels at the same time such that the readoutperiods for the two or more pixel arrays occur at the same time or atapproximately the same time. In an embodiment, the endoscopic imagingsystem includes multiple emitters that are each individual synced withone or more pixel arrays of a plurality of pixel arrays. Informationfrom a plurality of pixel arrays may be combined to generatethree-dimensional image frames and video streams.

It will be appreciated that the teachings and principles of thedisclosure may be used in a reusable device platform, a limited usedevice platform, a re-posable use device platform, or a singleuse/disposable device platform without departing from the scope of thedisclosure. It will be appreciated that in a re-usable device platforman end-user is responsible for cleaning and sterilization of the device.In a limited use device platform, the device can be used for somespecified amount of times before becoming inoperable. Typical new deviceis delivered sterile with additional uses requiring the end-user toclean and sterilize before additional uses. In a re-posable use deviceplatform, a third-party may reprocess the device (e.g., cleans, packagesand sterilizes) a single-use device for additional uses at a lower costthan a new unit. In a single use/disposable device platform a device isprovided sterile to the operating room and used only once before beingdisposed of.

EXAMPLES

The following examples pertain to preferred features of furtherembodiments:

Example 1 is a system. The system includes an emitter for emittingpulses of electromagnetic radiation and an image sensor comprising apixel array for sensing reflected electromagnetic radiation. The systemincludes a plurality of bidirectional data pads in the image sensor foroutputting image data and receiving configuration data. The systemincludes a controller in electronic communication with the image sensorand the emitter. The system is such that at least a portion of thepulses of electromagnetic radiation emitted by the emitter comprises oneor more of: electromagnetic radiation having a wavelength from about 513nm to about 545 nm; from about 565 nm to about 585 nm; from about 900 nmto about 1000 nm; an excitation wavelength of electromagnetic radiationthat causes a reagent to fluoresce; or a laser mapping pattern.

Example 2 is a system as in Example 1, further comprising: an oscillatordisposed in the controller; and a frequency detector in electroniccommunication with controller to control a clock frequency of the imagesensor in response to signals from the controller that correspond to thefrequency of the oscillator.

Example 3 is a system as in any of Examples 1-2, wherein electroniccommunication through each of the plurality of bidirectional pads isperformed in defined phases comprising: a rolling readout phase duringwhich the image data is output from the image sensor through theplurality of bidirectional pads to the controller; a service line phaseduring which non-image data is output from the image sensor through theplurality of bidirectional pads to the controller; and a configurationphase during which image sensor configuration data is received by theimage sensor from the controller through the plurality of bidirectionalpads; wherein image sensor data output lines are reversed during theconfiguration phase; and wherein a clock data recovery circuit isunlocked from an oscillator disposed in the controller when the imagesensor data output lines are reversed.

Example 4 is a system as in any of Examples 1-3, wherein clock signaldata is transmitted during the service line phase and the configurationphase and is not transmitted during the rolling readout phase.

Example 5 is a system as in any of Examples 1-4, wherein the imagesensor does not comprise a dedicated input synchronization clock padsuch that a total number of bidirectional pads in the image sensor isreduced.

Example 6 is a system as in any of Examples 1-5, further comprising anoscillator disposed in the controller for providing a reference clockfrequency to synchronize incoming sensor data.

Example 7 is a system as in any of Examples 1-6, further comprising atleast one transition within pixel serial data created by the pixel arrayof the image sensor, wherein the pixel serial data is replaced in thepixel array according to synchronization determined by clock signaldata.

Example 8 is a system as in any of Examples 1-7, further comprising: aphase lock loop (PLL) comprising PLL image sensor blocks and PLLcontroller blocks; data lines electrically connecting the PLL imagesensor blocks and the PLL controller blocks; and configuration lineselectrically connecting the PLL image sensor blocks and the PLLcontroller blocks; wherein an oscillator disposed in the controller anda data recovery circuit are used to lock on to incoming data received bythe controller from the image sensor.

Example 9 is a system as in any of Examples 1-8, wherein the imagesensor is configured to generate a plurality of exposure frames, whereineach of the plurality of exposure frames corresponds to a pulse ofelectromagnetic radiation emitted by the emitter.

Example 10 is a system as in any of Examples 1-9, wherein the pixelarray of the image sensor senses reflected electromagnetic radiation togenerate the plurality of exposure frames during a readout period of thepixel array, wherein the readout period is a duration of time whenactive pixels in the pixel array are read.

Example 11 is a system as in any of Examples 1-10, wherein at least aportion of the plurality of exposure frames are combined to form animage frame.

Example 12 is a system as in any of Examples 1-11, further comprising: avoltage controlled oscillator; a phase lock loop based on a charge pumpfor driving the voltage controlled oscillator; and a phase lock loopbased on a digital-to-analog converter for driving the voltagecontrolled oscillator.

Example 13 is a system as in any of Examples 1-12, wherein the emitteris configured to emit, during a pulse duration, a plurality ofsub-pulses of electromagnetic radiation having a sub-duration shorterthan the pulse duration.

Example 14 is a system as in any of Examples 1-13, wherein one or moreof the pulses of electromagnetic radiation emitted by the emittercomprise electromagnetic radiation emitted at two or more wavelengthssimultaneously as a single pulse or a single sub-pulse.

Example 15 is a system as in any of Examples 1-14, wherein at least aportion of the pulses of electromagnetic radiation emitted by theemitter is a fluorescence emission for exciting a fluorescent reagent,wherein the fluorescence emission results in a fluorescence exposureframe created by the image sensor, and wherein the controller isconfigured to provide the fluorescence exposure frame to a correspondingfluorescence system that determines a location of a critical tissuestructure within a scene based on the fluorescence exposure frame.

Example 16 is a system as in any of Examples 1-15, wherein thecontroller is further configured to: receive the location of thecritical tissue structure from the corresponding fluorescence system;generate an overlay frame comprising the location of the critical tissuestructure; and combine the overlay frame with a color image framedepicting the scene to indicate the location of the critical tissuestructure within the scene.

Example 17 is a system as in any of Examples 1-16, wherein sensing thereflected electromagnetic radiation by the pixel array comprisesgenerating a laser mapping exposure frame by sensing reflectedelectromagnetic radiation resulting from the emitter pulsing the lasermapping pattern, and wherein the controller is further configured to:provide the laser mapping exposure frame to a corresponding lasermapping system that determines a topology of the scene and/or dimensionsof one or more objects within the scene; provide the location of thecritical tissue structure to the corresponding laser mapping system; andreceive a topology and/or dimension of the critical tissue structurefrom the corresponding laser mapping system.

Example 18 is a system as in any of Examples 1-17, wherein the criticalstructure comprises one or more of a nerve, a ureter, a blood vessel, anartery, a blood flow, or a tumor.

Example 19 is a system as in any of Examples 1-18, wherein thecontroller is configured to synchronize timing of the pulses ofelectromagnetic radiation during a blanking period of the image sensor,wherein the blanking period corresponds to a time between a readout of alast row of active pixels in the pixel array and a beginning of a nextsubsequent readout of active pixels in the pixel array.

Example 20 is a system as in any of Examples 1-19, wherein two or morepulses of electromagnetic radiation emitted by the emitter result in twoor more instances of reflected electromagnetic radiation that are sensedby the pixel array to generate two or more exposure frames that arecombined to form an image frame.

Example 21 is a system as in any of Examples 1-20, wherein the imagesensor comprises a first image sensor and a second image sensor suchthat the image sensor can generate a three-dimensional image.

Example 22 is a system as in any of Examples 1-21, wherein the emitteris configured to emit a sequence of pulses of electromagnetic radiationrepeatedly sufficient for generating a video stream comprising aplurality of image frames, wherein each image frame in the video streamcomprises data from a plurality of exposure frames, and wherein each ofthe exposure frames corresponds to a pulse of electromagnetic radiation.

Example 23 is a system as in any of Examples 1-22, wherein the pulses ofelectromagnetic radiation are emitted in a pattern of varyingwavelengths of electromagnetic radiation, and wherein the emitterrepeats the pattern of varying wavelengths of electromagnetic radiation

Example 24 is a system as in any of Examples 1-23, wherein at least aportion of the pulses of electromagnetic radiation emitted by theemitter comprises a fluorescence emission for exciting a fluorescentreagent, wherein the fluorescence emission comprises the electromagneticradiation having the wavelength from about 770 nm to about 790 nm andthe electromagnetic radiation having the wavelength from about 795 nm toabout 815 nm.

Example 25 is a system as in any of Examples 1-24, wherein at least aportion of the pulses of electromagnetic radiation emitted by theemitter is an excitation wavelength for fluorescing a reagent, andwherein at least a portion of the reflected electromagnetic radiationsensed by the pixel array is a relaxation wavelength of the reagent.

Example 26 is a system as in any of Examples 1-25, wherein at least aportion of the pulses of electromagnetic radiation comprise a redwavelength, a green wavelength, a blue wavelength, and a fluorescencewavelength such that reflected electromagnetic radiation sensed by thepixel array corresponding to each of the red wavelength, the greenwavelength, the blue wavelength, and the fluorescence wavelength can beprocessed to generate a Red-Green-Blue (RGB) image comprising an overlayof fluorescence imaging data, wherein the fluorescence wavelength ofelectromagnetic radiation comprises the electromagnetic radiation havingthe wavelength from about 770 nm to about 790 nm and the electromagneticradiation having the wavelength from about 795 nm to about 815 nm.

Example 27 is a system as in any of Examples 1-26, further comprising afilter that filters electromagnetic radiation having a wavelength fromabout 770 nm to about 790 nm.

Example 28 is a system as in any of Examples 1-27, further comprising afilter that filters electromagnetic radiation having a wavelength fromabout 795 nm to about 815 nm.

Example 29 is a system as in any of Examples 1-28, wherein sensingreflected electromagnetic radiation by the pixel array comprisesgenerating a laser mapping exposure frame by sensing reflectedelectromagnetic radiation resulting from the emitter pulsing the lasermapping pattern, wherein the laser mapping exposure frame comprisesinformation for determining real time measurements comprising one ormore of: a distance from an endoscope to an object; an angle between anendoscope and the object; or surface topology information about theobject.

Example 30 is a system as in any of Examples 1-29, wherein the lasermapping exposure frame comprises information for determining the realtime measurements to an accuracy of less than 10 centimeters.

Example 31 is a system as in any of Examples 1-30, wherein the lasermapping exposure frame comprises information for determining the realtime measurements to an accuracy of less than one millimeter.

Example 32 is a system as in any of Examples 1-31, wherein at least aportion of the pulses of electromagnetic radiation emitted by theemitter comprises a plurality of tool-specific laser mapping patternsfor each of a plurality of tools within a scene.

Example 33 is a system as in any of Examples 1-32, wherein the lasermapping pattern emitted by the emitter comprises a first output and asecond output that are independent from one another, wherein the firstoutput is for light illumination and the second output is for tooltracking.

Example 34 is a system as in any of Examples 1-33, wherein at least aportion of the pulses of electromagnetic radiation emitted by theemitter is a hyperspectral emission for eliciting a spectral response,wherein the hyperspectral emission results in a hyperspectral exposureframe created by the image sensor, and wherein the controller isconfigured to provide the hyperspectral exposure frame to acorresponding hyperspectral system that determines a location of acritical tissue structure within a scene based on the hyperspectralexposure frame.

Example 35 is a system as in any of Examples 1-34, wherein thecontroller is further configured to: receive the location of thecritical tissue structure from the corresponding hyperspectral system;generate an overlay frame comprising the location of the critical tissuestructure; and combine the overlay frame with a color image framedepicting the scene to indicate the location of the critical tissuestructure within the scene.

Example 36 is a system as in any of Examples 1-35, wherein sensing thereflected electromagnetic radiation by the pixel array comprisesgenerating a laser mapping exposure frame by sensing reflectedelectromagnetic radiation resulting from the emitter pulsing the lasermapping pattern, and wherein the controller is further configured to:provide the laser mapping exposure frame to a corresponding lasermapping system that determines a topology of the scene and/or dimensionsof one or more objects within the scene; provide the location of thecritical tissue structure to the corresponding laser mapping system; andreceive a topology and/or dimension of the critical tissue structurefrom the corresponding laser mapping system.

Example 37 is a system as in any of Examples 1-36, wherein the criticalstructure comprises one or more of a nerve, a ureter, a blood vessel, anartery, a blood flow, or a tumor.

Example 38 is a system as in any of Examples 1-37, wherein at least aportion of the plurality of pulses of electromagnetic radiation comprisea hyperspectral emission comprising one of: electromagnetic radiationhaving a wavelength from about 513 nm to about 545 nm andelectromagnetic radiation having a wavelength from about 900 nm to about1000 nm; or electromagnetic radiation having a wavelength from about 565nm to about 585 nm and electromagnetic radiation having a wavelengthfrom about 900 nm to about 1000 nm; wherein sensing reflectedelectromagnetic radiation by the pixel array comprises generating ahyperspectral exposure frame based on the hyperspectral emission.

Example 39 is a system as in any of Examples 1-38, wherein sensingreflected electromagnetic radiation by the pixel array comprisesgenerating a laser mapping exposure frame based on emission by theemitter of the laser mapping pattern, and wherein the controller isconfigured to: provide the hyperspectral exposure frame to acorresponding hyperspectral system that determines a location of acritical tissue structure based on the hyperspectral exposure frame;receive the location of the critical tissue structure from thecorresponding hyperspectral system; provide the laser mapping exposureframe to a corresponding laser mapping system that determines a topologyof the scene and/or dimensions of one or more objects within the scene;provide the location of the critical tissue structure to thecorresponding laser mapping system; and receive a topology and/ordimension of the critical tissue structure from the corresponding lasermapping system; wherein the critical tissue structure is one or more ofa nerve, a ureter, a blood vessel, an artery, a blood flow, canceroustissue, or a tumor.

It will be appreciated that various features disclosed herein providesignificant advantages and advancements in the art. The following claimsare exemplary of some of those features.

In the foregoing Detailed Description of the Disclosure, variousfeatures of the disclosure are grouped together in a single embodimentfor the purpose of streamlining the disclosure. This method ofdisclosure is not to be interpreted as reflecting an intention that theclaimed disclosure requires more features than are expressly recited ineach claim. Rather, inventive aspects lie in less than all features of asingle foregoing disclosed embodiment.

It is to be understood that any features of the above-describedarrangements, examples, and embodiments may be combined in a singleembodiment comprising a combination of features taken from any of thedisclosed arrangements, examples, and embodiments.

It is to be understood that the above-described arrangements are onlyillustrative of the application of the principles of the disclosure.Numerous modifications and alternative arrangements may be devised bythose skilled in the art without departing from the spirit and scope ofthe disclosure and the appended claims are intended to cover suchmodifications and arrangements.

Thus, while the disclosure has been shown in the drawings and describedabove with particularity and detail, it will be apparent to those ofordinary skill in the art that numerous modifications, including, butnot limited to, variations in size, materials, shape, form, function andmanner of operation, assembly and use may be made without departing fromthe principles and concepts set forth herein.

Further, where appropriate, functions described herein can be performedin one or more of: hardware, software, firmware, digital components, oranalog components. For example, one or more application specificintegrated circuits (ASICs) or field programmable gate arrays (FPGAs)can be programmed to carry out one or more of the systems and proceduresdescribed herein. Certain terms are used throughout the followingdescription and claims to refer to particular system components. As oneskilled in the art will appreciate, components may be referred to bydifferent names. This document does not intend to distinguish betweencomponents that differ in name, but not function.

The foregoing description has been presented for the purposes ofillustration and description. It is not intended to be exhaustive or tolimit the disclosure to the precise form disclosed. Many modificationsand variations are possible in light of the above teaching. Further, itshould be noted that any or all the aforementioned alternateimplementations may be used in any combination desired to formadditional hybrid implementations of the disclosure.

Further, although specific implementations of the disclosure have beendescribed and illustrated, the disclosure is not to be limited to thespecific forms or arrangements of parts so described and illustrated.The scope of the disclosure is to be defined by the claims appendedhereto, any future claims submitted here and in different applications,and their equivalents.

What is claimed is:
 1. A system comprising: an emitter that emits aplurality of pulses of electromagnetic radiation; an image sensorcomprising a pixel array that detects electromagnetic radiation; aplurality of bidirectional data pads on the image sensor for outputtingimage data and receiving configuration data; and a controller inelectronic communication with the image sensor and the emitter; whereinat least a portion of the plurality of pulses of electromagneticradiation emitted by the emitter comprises electromagnetic radiation ina laser mapping pattern and further comprises one or more of:electromagnetic radiation having a wavelength from about 513 nm to about545 nm; electromagnetic radiation having a wavelength from about 565 nmto about 585 nm; electromagnetic radiation having a wavelength fromabout 900 nm to about 1000 nm; or a fluorescence excitation wavelengthof electromagnetic radiation; wherein the controller synchronizesoperations of the image sensor and the emitter such that the imagesensor outputs data corresponding with the plurality of pulses ofelectromagnetic radiation emitted by the emitter.
 2. The system of claim1, further comprising: an oscillator disposed in the controller; and afrequency detector in electronic communication with the controller tocontrol a clock frequency of the image sensor in response to signalsfrom the controller that correspond to the frequency of the oscillator.3. The system of claim 1, wherein electronic communication through eachof the plurality of bidirectional pads is performed in defined phasescomprising: a rolling readout phase during which image data is outputfrom the image sensor through the plurality of bidirectional pads to thecontroller; a service line phase during which non-image data is outputfrom the image sensor through the plurality of bidirectional pads to thecontroller; and a configuration phase during which image sensorconfiguration data is received by the image sensor from the controllerthrough the plurality of bidirectional pads; wherein image sensor dataoutput lines are reversed during the configuration phase; and wherein aclock data recovery circuit is unlocked from an oscillator disposed inthe controller when the image sensor data output lines are reversed. 4.The system of claim 3, wherein clock signal data is transmitted duringthe service line phase and the configuration phase and is nottransmitted during the rolling readout phase.
 5. The system of claim 1,wherein the image sensor does not comprise a dedicated inputsynchronization clock pad such that a total number of data pads in theimage sensor is reduced.
 6. The system of claim 1, further comprising anoscillator disposed in the controller for providing a reference clockfrequency to synchronize incoming data received from the image sensor.7. The system of claim 1, wherein the image sensor is configured tooutput at least one transition within pixel serial data sensed by thepixel array, and wherein the pixel serial data is replaced in the pixelarray according to synchronization determined by clock signal data. 8.The system of claim 1, further comprising: a phase lock loop (PLL)comprising PLL image sensor blocks and PLL controller blocks; data lineselectrically connecting the PLL image sensor blocks and the PLLcontroller blocks; and configuration lines electrically connecting thePLL image sensor blocks and the PLL controller blocks; wherein anoscillator disposed in the controller and a data recovery circuit areused to lock on to incoming data received by the controller from theimage sensor.
 9. The system of claim 1, wherein the image sensor outputsthe data for generating a plurality of exposure frames, and wherein eachof the plurality of exposure frames corresponds to one or more pulses ofthe plurality of pulses of electromagnetic radiation emitted by theemitter, and wherein the image sensor outputs data for generating alaser mapping exposure frame in response to the emitter pulsing theelectromagnetic radiation in the laser mapping pattern.
 10. The systemof claim 9, wherein the image sensor reads out readout data forgenerating an exposure frame during a readout period of the pixel array,and wherein the readout period is a duration of time when active pixelsin the pixel array are read.
 11. The system of claim 9, wherein thecontroller is configured to combine two or more of the plurality ofexposure frames to generate an image frame comprising color image dataand one or more of multispectral image data, laser mapping image data,or fluorescence image data.
 12. The system of claim 1, furthercomprising: a voltage controlled oscillator; a phase lock loop based ona charge pump for driving the voltage controlled oscillator; and a phaselock loop based on a digital-to-analog converter for driving the voltagecontrolled oscillator.
 13. The system of claim 1, wherein the emitter isconfigured to emit, during a pulse duration, a plurality of sub-pulsesof electromagnetic radiation having a sub-duration shorter than thepulse duration.
 14. The system of claim 1, wherein one or more of theplurality of pulses of electromagnetic radiation emitted by the emittercomprises electromagnetic radiation emitted at two or more wavelengthssimultaneously as a single pulse or a single sub-pulse.
 15. The systemof claim 1, wherein at least a portion of the plurality of pulses ofelectromagnetic radiation emitted by the emitter is the fluorescenceexcitation wavelength, and wherein the pixel array detects theelectromagnetic radiation and outputs data for a fluorescence exposureframe, and wherein the controller is configured to provide thefluorescence exposure frame to a corresponding fluorescence system thatdetermines a location of a tissue structure within a scene based on thefluorescence exposure frame.
 16. The system of claim 15, wherein thecontroller is further configured to: receive the location of the tissuestructure from the corresponding fluorescence system; generate anoverlay frame comprising the location of the tissue structure; andcombine the overlay frame with a color image frame depicting the sceneto indicate the location of the tissue structure within the scene. 17.The system of claim 16, wherein the pixel array detects theelectromagnetic radiation and outputs data for a laser mapping exposureframe in response to the emitter pulsing the electromagnetic radiationin the laser mapping pattern, and wherein the controller is furtherconfigured to: provide the laser mapping exposure frame to acorresponding laser mapping system that determines a topology of thescene and/or dimensions of one or more objects within the scene; providethe location of the tissue structure to the corresponding laser mappingsystem; and receive a topology and/or dimension of the tissue structurefrom the corresponding laser mapping system.
 18. The system of claim 17,wherein the tissue structure comprises one or more of a nerve, a ureter,a blood vessel, an artery, a blood flow, or a tumor.
 19. The system ofclaim 1, wherein the controller is configured to synchronize timing ofthe pulses of electromagnetic radiation during a blanking period of theimage sensor, wherein the blanking period corresponds to a time betweena readout of a last row of active pixels in the pixel array and abeginning of a next subsequent readout of active pixels in the pixelarray.
 20. The system of claim 1, wherein two or more pulses ofelectromagnetic radiation emitted by the emitter result in two or moreinstances of reflected electromagnetic radiation that are sensed by thepixel array to generate two or more exposure frames that are combined toform an image frame.
 21. The system of claim 1, wherein the image sensorcomprises a first image sensor and a second image sensor such that theimage sensor can generate a three-dimensional image.
 22. The system ofclaim 1, wherein the emitter is configured to emit a sequence of pulsesof electromagnetic radiation repeatedly sufficient for generating avideo stream comprising a plurality of image frames, wherein each imageframe in the video stream comprises data from a plurality of exposureframes, and wherein each of the plurality of exposure frames correspondsto one or more pulses of the plurality of pulses of electromagneticradiation.
 23. The system of claim 1, wherein at least a portion of theplurality of pulses of electromagnetic radiation emitted by the emitteris an excitation wavelength for fluorescing a reagent, and wherein atleast a portion of the reflected electromagnetic radiation sensed by thepixel array is a relaxation wavelength of the reagent.
 24. The system ofclaim 1, wherein sensing reflected electromagnetic radiation by thepixel array comprises generating a laser mapping exposure frame bysensing reflected electromagnetic radiation resulting from the emitterpulsing the electromagnetic radiation in the laser mapping pattern, andwherein the laser mapping exposure frame comprises information fordetermining real time measurements comprising one or more of: a distancefrom an endoscope to an object; an angle between an endoscope and theobject; or surface topology information about the object.
 25. The systemof claim 24, wherein the laser mapping exposure frame comprisesinformation for determining the real time measurements to an accuracy ofless than 10 centimeters.
 26. The system of claim 24, wherein the lasermapping exposure frame comprises information for determining the realtime measurements to an accuracy of less than one millimeter.
 27. Thesystem of claim 1, wherein at least a portion of the plurality of pulsesof electromagnetic radiation emitted by the emitter comprises aplurality of tool-specific laser mapping patterns for each of aplurality of tools within a scene.
 28. The system of claim 1, whereinthe pulse of the electromagnetic radiation in the laser mapping patterncomprises a first output and a second output that are independent fromone another, and wherein the first output is for light illumination andthe second output is for tool tracking.
 29. The system of claim 1,wherein at least a portion of the plurality of pulses of electromagneticradiation comprises a multispectral emission comprising one or more of:the electromagnetic radiation having the wavelength from about 513 nm toabout 545 nm and the electromagnetic radiation having the wavelengthfrom about 900 nm to about 1000 nm; or the electromagnetic radiationhaving the wavelength from about 565 nm to about 585 nm and theelectromagnetic radiation having the wavelength from about 900 nm toabout 1000 nm; wherein sensing reflected electromagnetic radiation bythe pixel array comprises generating a multispectral exposure frame inresponse to the emitter pulsing the the multispectral emission.
 30. Thesystem of claim 29, wherein the image sensor senses a laser mappingexposure frame in response to the emitter pulsing the electromagneticradiation in the laser mapping pattern, and wherein the controller isconfigured to: provide the multispectral exposure frame to acorresponding multispectral system that determines a location of atissue structure based on the multispectral exposure frame; receive thelocation of the tissue structure from the corresponding multispectralsystem; provide the laser mapping exposure frame to a correspondinglaser mapping system that determines a topology of the scene and/ordimensions of one or more objects within the scene; provide the locationof the tissue structure to the corresponding laser mapping system; andreceive a topology and/or dimension of the critical tissue structurefrom the corresponding laser mapping system; wherein the tissuestructure is one or more of a nerve, a ureter, a blood vessel, anartery, a blood flow, cancerous tissue, or a tumor.